So, I am essentially about to write my first novel. I've written a lot of short stories and poetry, and I wanted to see if I am up for a kind of challenge. Any tips or ideas I should consider while writing? Note: I'm not looking for a storyline or plot. That's already worked out.
Think about your characters visualise them in the setting you have created. Work over the plot in your mind. Do this for as long as you can before you start writing. You must know your characters and know how they will react in the setting you have thrown them into. They should be 'real' to you, how else are you going to write them.
Write everything you want to tell the reader ink, paper, and coffee farmers be damned. Then go back and only include what the reader needs to know. It hurts. I cut 10,000 words out of my MS and they were all important to me. However, they were not pertinent to the flow. In my new MS I will do the same. It is those words you keep from the reader that build your character.
Don't waste words or use them to no purpose. For example, "so" and "essentially" in the first sentence of your post. Neither adds anything.