Don’t speak like that about yourself! You’re learning, as we all are! No one was born programming.
I’ve not used this way of passing to a socket before, but it looks like from the nginx docs that you’d want a final :/ to indicate the base URL?
proxy_pass http://unix:/home/ubuntu/exostocksaas/app.sock:/;
One thing to do in this situation is figure out which thinig is giving the 404.
Where are you passing the app module to gunicorn? If you run this command alone, does iti work?