Question about gas

Hey, sorry for the obviously noob question, i mined some eth in 2017 (just 0.028, really not much at all), and i just wanted to transfer it to an exchange i use, but it says "the minimum gas should be 50000". What exactly does that mean? For example, the usual fee for average speed is like 100gwei, how is the price calculated? i should set the gas limit to 50000 and use 100gwei to send it? Thanks, and sorry for the dumb question (also, i'm using etherwallet, since that's what i used at the time)