Don't try to stand out, co-workers get jealous quickly and / or will take advantage of your 'hard work'. Try to be in between "friends and professional coworker" I know it's a job and I don't mean to say don't take it seriously, just don't let it interfere with your health and life. Some people who run fast food places are not as educated, bosses will tell you 'what to do', do it right, etc.. I just thought of it as a way of making pocket money.

Ask yourself why you're afraid to get fired, they need you that's why they hired you.
You will get rude customers. Dont take it personally - anybody can just walk in having a bad day and take it out on a young, new worker. When I used to work at a fast food place, a woman would ask how much I made, tell me she felt sorry for me, that I looked old and tired, and said she is going home to her husband to have a nice dinner and felt sorry I had to work! At least I work #&%^