Hello Marina, They are both phrasal verbs and can have different meanings in different contexts! A bomb can go off (explode) or you can go off of somebody (not like any more) I get off work at six (to finish work/school) or Did you get the baby off? (off to sleep) There are other meanings but as I said you need the context. Hope this helps Bob

Go off can when used on food means to rot, "The fruit will go off". It can mean yell when used on a person, "He went off" means the same as "He started yelling". It can also mean fire or explode when talking about guns and bombs. "The gun will go off" means the same as "The gun will fire". There may be more meanings but I can't think of them. Get off means to be released from something. When you finish work you "get off work", when you aren't punished for something you did you "got off". Be careful though because it also has sexual meanings so if you don't use it correctly you might say something unintentionally funny.

Very relevant question. I do think the meanings and usages vary regionally. I know here 'get off' often has sexual connotations.