One is the result of the other. Get dressed = Action of putting your clothes on (getting dressed is the opposite of taking your clothes off) Be dressed = State of having clothes on( being dressed is the opposite of being naked) Your friend messages you early in the morning and invites you out for breakfast - you're still in your pyjamas. You message back and say 'OK, I just need to get dressed'. You put on your shirt, trousers, shoes etc and then message back 'Right, I'm dressed now', I'll be there in a minute'. Likewise, 'get drunk' is the action of drinking alcohol - maybe sharing some beers with your friends in the pub. 'Be drunk' is the result - maybe when it's time to go home and you realise that you can't walk in a straight line. You sensibly decide to leave your car where it is and take a taxi home.

Dictionaries are static. ITalki or similar forums help.

One is a state of being (be sick) and one is an action (get sick) (= on the way to being sick)

Dictionaries are useful. Oxford Learner's Dictionaries https://www.oxfordlearnersdictionaries.com/definition/english/get?q=get definition 11 Google is useful. google "what is the difference between the verbs get and be?" https://www.google.com/search?client=safari&rls=en&q=what+is+the+difference+between+the+verbs+get+and+be%3F&ie=UTF-8&oe=UTF-8 https://www.quora.com/What-is-the-difference-between-the-verbs-to-do-and-to-be