I'm editing a story of mine, and I've noticed all the tense mistakes I made. So now that my entire story is changed into the correct tense, I feel that it's missing something. Now, I want to have half of the story in past tense, and the other half in present tense. IE: An example of this would be from my short story: A slip of white paper hoverd before Cora, enticing her to take it. She was at lost as to what to do until she saw the gold letterings on the top. It read: My name will be: ______ On the desk there is a book which Cora found to consist of names, and a pen. She grabs(?) the slip and takes(?) the marker to hand. She hesitates(?). The bold is the past tense. The underlinings are the words that I have changed into present tense. Half way before this point, my story has been in past tense. Yet from there on, my whole story focuses into present tense. Is this acceptable as long as it's consistent? I want the reader to feel like they've been living the past events of my MC, before she's into the critical moment, which goes into present tense.
I'm not sure the reader will understand your intent, if you just switch tense in the middle of the story. It can be shown more clearly if you, for example, let the main character think back on past events, or read his/her own diary.
I think this topic has been covered extensively in earlier threads. Look around a bit and you'll find many discussions on the topic. Yes, there are times when you can/(have to) switch tense (refer earlier threads as suggested above), and I have seen writers effectively switching present and past tense in their stories here in this forum. But, if you are a beginner I strongly suggest you stick to past or the present tense throughout the story. And I don't see why you can't achieve 'readers living the events' using only past tense. With good sentence structures and verbs, you can do it.
I don't think switching tense would work here, unless you show a very clear break, ie. breaking the story into two acts / parts. How I Live Now, by Meg Rosoff, is a good example of this.
You just have to be able to do it effectively. If you do it, and pull it off, then great. If you're not sure you can do it effectively, and it ends up awkward or puts off a reader, then you're better off without it. I've seen some good authors pull of a POV change mid-paragraph (if not mid-sentence). Virginia Woolf did it, for example. But as a rule, it's not a good idea to try it because you're more likely to screw it up than pull it off
what you've shown makes no sense to me at all... the reason you give for wanting to switch between past and present, doesn't make sense to me, either... plus, you'd have to be an exceptionally good writer to pull it off successfully... as noted above, beginners shouldn't try the fancy stuff... and btw, your excerpt has major goofs needing fixing... such as, 'hoverd' and 'was at lost as to'... the second part itself has a muddle of both tenses, is not only in present...
If I were you, I would stick to the past tense all over the story--of course except in the live conversations or dialogue as I used to see in novels. Nevertheless, you can go through experimental writing and do something new or unusual.
Judging from the amount of errors in those few sentences you have posted, I would strongly suggest sticking to the past tense until you can actually get a grip on the different tenses. Work on writing accurately before you start playing around.