Give your employer at least two weeks notice
In the professional world, its pretty standard to give employers two weeks notice before your last day. Make sure you specify exactly when your last day will be to avoid confusion. Its always nice if you actually type up a two weeks notice that specifies your last day. Be sure to include a thank you for everything this job has taught you. Even if you didn't learn anything and hated every second of it, make it up! Its better to be polite, than bash a potential reference. Plus in future interviews for jobs, they'll most likely ask you about your experiences at this job now. It looks really bad if you say negative things about past employers so its better to come up with amo now, than to accidentally catch a case of word-vomit during an interview.
Stand your ground
Easier said than done. My name is synonymous with pushover when it comes to jobs. If someone asks me to work an extra 10 hours for them, I do it. I'm like a yes-man when it comes to jobs. But when quitting, you have to be able to stand your round and tell your boss/manager that you need to quit- no questions asked. Even if they beg you to stay, or tell you that they can work around your schedule, stick to your original plan and don't back down. Do what's best for you. Don't be afraid to tell them you're quitting if its truly in your best interest to quit. Obviously you weren't in it for the long haul. I don't think any of you were looking to make a career out of painting houses, scooping ice cream, or baging groceries right?
This kinda goes along with the previous, but managers are like dogs- they can smell fear. Idk actually I just made that up. But if you go up to them shaking and cant even make eye contact with them your argument will be much less convincing. Delivery is key. Its much better to say something like "hey, I've been thinking a lot about my upcoming responsibilities during the school year and don't think its realistic to continue working here. It would be unfair for me to make a commitment to you that I know I won't be able to uphold, so I think its best for me to put in my two weeks now." Instead of mumbling something random out of nervousness. Or my personal favorite, saying "hey, I need to talk to you about something...I um...like your shoes?" Yes, you got it- that happened to me once. Guilty as charged. Avoid awkward encounters and just get it over with by knowing what you're going to say beforehand and being confident about it. No need to be scared! You'll feel much more relieved when you finalllyyy got the nerve to tell em whats up.
Just pretend like you're Queen B if you need a confidence boost.
Don't talk back to your manager or boss and don't talk about them behind their backs. It'll probably come back to haunt you, so why not play it safe? You have two weeks left; I think you can handle it.
Keep smiling til the very end
You wanna end on a good note. You want your coworkers to remember you in a positive light. Whenever I get a new job, I'm always told stories about "that girl" who used to work there that was just horrible, snotty, crazy, etc. Don't be that girl. Be the girl who's smiling til the very second she leaves those doors. Then
RUN FOR THE HILLS YOU'RE FREE!!!! ...Until next year