Here's the thing, my story starts by following two characters but not personally, so while you're told that they're hurrying, you're not told too in-depth of how they're feeling (they heard someone scream and got concerned and went to help out, I'm not going to mention any physical experiences, just their worry and that's about it). The person they're trying to find and help is the guy whose point of view I'd like to make use of since he'll be the main POV for a while afterwards. Would it come off as odd if I suddenly start describing the main character's experiences if the story started off with two other characters and they just stumbled onto this guy? I was thinking I may just start off with him at the beginning as he gets rescued by the two others instead, though since the two other characters become close friends of the main character (and their culture then features importantly for the next couple of chapters), I wanted to highlight their good nature.
I think that this is risky. I remember reading a friend's story, with a very interesting main character who continued for a few pages, and who then turned out to be in the story purely to be rescued by the "real" main character. The result was that those few pages were completely wasted. We met a character, we liked him, we bonded with him, and then we were supposed to do the whole thing again with a whole new main character. Each reader has only so much patience for "story start-up". Your risk here is that that patience is used up before your reader even sees the real main character.
I agree with ChickenFreak (there's a sentence I never expected to write on a Tuesday morning - loving these forum avatars!) I wouldn't do it either as it's too distracting for the reader. You could break the scene into two. Stylistically chapters can use a dinkus (three star break) or numbers to put in multiple scenes, so you could use that instead (it's the equivalent of a semi-colon for a scene and you can change POV without confusing the reader as much.
I'm not even sure you get to @ChickenFreak's concern because of the highlighted portion. If I'm reading this correctly, we start out following two guys without being given a reason to want to follow them. You want to draw the reader in. Much better would be to focus on the guy in danger, since he's going to be your MC, anyway. Put the reader in the MC's shoes, unable to get out of whatever dastardly predicament you've put him in. If you start with him being rescued, you lose a chance to draw the reader in and build some suspense. A problem I wrestled with for a long time in my writing was creating a problem for the MC and then resolving it too quickly. The problem is the reason the reader is going to keep turning the pages. Close friends is one thing, but will they figure prominently in the story? If so, then you might be able to start out as you planned - focusing on the rescuers - but if you do that, you need to let the reader know 1) how important the MC is to the two of them and how concerned/frightened they are for him; 2) why; 3) just how much danger the MC is really in. You have to put the reader in their shoes, which is to say very personally. In so doing, you are actually preparing to transition the reader to caring about the MC. Good luck.
Well, heck. That's such a good response, @EdFromNY , I'm getting to know the story myself. I'm sure you've really helped @CMastah here! Great insight and advice.
For questions like this, my answer is usually the same: it depends on the skill of the writer. It's not inherently bad or wrong to switch the POV like this, but it can be if not handled properly. You, as the writer, need to show us why this method works the best. While I don't necessarily agree with the others that the friends need to be important characters, it's certainly something to consider.
Thanks guys, to shed more light on what happens: Two guys from a stone age civilization (I feel it necessary to explain this because I'd mention that they're carrying stone weapons and dressed in fur) run towards a scream they hear, they assume a child got attacked in the nearby woods. When they reach the area, they find the MC who is badly injured (and is only just discovering their civilization, he's not one of them) and help him out at which point the POV switches to him. While the two guys would be running towards the MC, I'd use the opportunity to mention their concern that a tribesman might've been attacked and perhaps some simple dialogue but primarily I wanted to throw hints at the oddity of the two characters (that being that they're stone age folk). The two characters would not even be named at this point (they'd be named shortly after meeting the main character) and one of them does become a somewhat important character later on. Seeing some of the responses here, I am a tad concerned about my intentions for my story. The thing is, the character who's introduced at the start of the story is NOT meant to be the protagonist, he befriends one of the tribesmen's kids and while the kid grows up and eventually leaves to discover normal society, the guy tags along/helps out (whilst the story revolves around that kid). The kid is meant to be the main character but at the start of the story, he's not even born yet and the novel follows him while he grows up into a teen who then decides to leave his tribe to see the modern world instead. The guy at the start will be very briefly seen as he's not around for the majority of the novel after the kid leaves the tribe. The part that's now got me a little worried is that the guy at the start of the novel features very heavily (as in it'll be mostly his POV during the time the kid is in the tribe) at the start, far more so than the kid (the kid features mostly at that point as being studied by the guy from the start). The child's innocent youth is seen here at the start but the primary POV will be on the guy who won't appear that much after the kid leaves the tribe (admittedly I do sense this may be a problem).
You're instincts are serving you well. It sounds to me that much of what you are beginning with is backstory, not the story itself. Perhaps one problem is that you are looking at your story in terms of the chronological order of events that make it up. But that isn't always the best way to tell a story - in fact, it frequently isn't. So, the first thing you need to decide for yourself is: what is the story you want to tell? Don't tell us, but decide for yourself. Next thing: how does your proposed beginning draw the reader into the story you want to tell? Is there a better way? My current favorite example is Rachel Simon's The Story of Beautiful Girl. A widow at a farmhouse stands and watches while local authorities take a young mother away in a car. Her baby lies asleep in the attic. The man who showed up a short while ago with the woman and her baby has ducked out a window. Neither the man nor the young mother talk, but just before she is forced into the car, the young mother whispers to the widow, "Hide her!" Just before the car pulls away, the widow calls out, "I will!" That's how the book starts. There is a lot of backstory - the young mother and the man have both escaped from an institution, to which the mother is being returned. The mother is developmentally disabled and willfully mute while the man is a deaf-mute John Doe who was taught only the sign language developed in segregated institutions in the American South. He isn't the baby's father, a guard at the institution is. The widow never had children and hasn't the first idea of how to care for one. But we don't know ANY of that at the beginning of the story. Just the baby, the promise, and the car driving off on a rainy night in rural Pennsylvania in the late 1960s. The backstory is revealed later, as it is needed by the reader.