What is the hardest part of writing a novel for you all

I’ve been trying to write this novel since high school but I’m having a hard time getting it down. I think of things as I’m trying to work on this one story, and it just makes it even harder to do. One of the biggest hardships for me is my characters. I have 6 (maybe 7, I haven’t decided yet) and I’m having a hard time making them all stand out. I don’t want any of them to be shoved into the background, and they all play important roles. <br><br>Any tips??