For your painting to be selected as a good and meaningful painting and sent to the gallery, a lot of work needs t be put into it.
The idea, get a meaningful idea first, your thesis determines your painting the most.
Artistic skills don't matter much, We have artificial intelligence on our side. You can generate paintings at a much more efficient rate than if you draw them. So try and focus on your lesson and theme more.
Trial and error help a lot, try and give the AI a lot of commands until you are delighted.
Try your best. This is very important, the more effort you put into your painting, the more rewarding it gets.
Have fun, it's the most essential part. We all grow as we learn and share ideas, don't be stressed, and don't be afraid to change and receive critique.