It's a game. Enjoy it for what it is. Don't try to make it something it's not. Things RPGs aren't: stories, movies, novels, creative writing exercises, a theater troupe, or improv.
There are randomizers in the game. They will produce random results. That's what they're there for. Don't get mad when the randomizers...gasp...produce random results. If you don't like randomizers, try to minimize your need to use them via roleplaying or play games that rely less on randomizers.
You are not your character. If your character dies, nothing bad happens to you. Laugh about the silly way they died and roll up a new one.
Don't force your kind of fun on others. Check with the rest of the group. What's fun for you might be nails on a chalkboard annoying for others. If whatever that thing is is so integral to your enjoyment of the game, find a group of like-minded players. Examples include, but are not limited to: funny voices, cosplay at the table, power gaming, RPG as acting, beer & pretzels style play, etc.
Don't argue with the referee during the game. They're in charge. If you don't like a call they made, ask for clarification. If you still don't like the answer talk to them about it after the game. Stopping the game so you can argue a call, rule, or ruling with the referee is about the most selfish thing you can do. Don't be that person.
Remember that no one cares about your war stories from past games, campaigns, or characters. If someone asks you, tell them. But literally no one will ever ask you. Why? Because they're here now to play now with these characters in this game. That's what the focus should be.