Have some important questions if anyone can help

I know nothing about coin collecting, but my great uncle passed last month and he gave the absurdly valuable coins to certain family but I've been finding many coins around the house, mostly of English. Italian Greek heritage. I have looked some of these up and some of them seem to potentially be worth alot, i think my uncle had them on purpose...but im also broke and dont collect this so can someone please explain how to tell which coins have value and if they do where to go to sell them? I desperately need money right now. these here are probably about 1/4 of all of them. one thing that comes to mind tho is there's a 1980 and 81 new pence "2p" coins...the 1981 one i keep seeing its worth hundreds cuz it wasnt supposed to say new pence that year or something...then I'll see people saying it's not worth sh* either way very confusing....