1) if you give a two weeks notice. Do it verbally. Don’t write it out and give it to your employer. If they ask you too, don’t. They won’t fire you because you can collect unemployment since they don’t have proof you intend to quit.
2) if you have another job lined up that doesn’t have a hard start date. Ask if you can start earlier if need be.
3) don’t let your boss be a dick to you once you tell them you’re leaving. If they act like an ass to you. Literally just walk away from them or tell them how you really feel about them. Stand up to them, you’re leaving anyway. Or just walk away and do something else. If they get aggressive with you, just pull out your phone and record them. They’ll shut up or you’ll have nice evidence to submit to a work place lawyer. Some law firms will take your case even if you can’t afford their normal rate.
If your boss tries to make you do extra work, shit work, or something out of your job scope. Just say no