Edit, edit, edit before submitting anything.
You cannot edit after 24 hours or after any upvote, whichever comes first.
Pay attention to the first line. It is what will be seen first.
Choose the right tags - they make a huge difference to who will see your posts.
Learn how to post images. The submissions look much better with a well chosen image.
Upvoting and commenting on other submissions is as important as submitting your own material.
Understanding SP and the terminology is going to take a lot of time.