I need help with learning moles…

Its not really tech but its science! (chemistry) We just started learning about moles? (Avogadro’s) 6.02 x 10^23…I have notes on it and I was told we haft to know the formulas on the test but we can use notes.He told us how to do it and all but its not clicking to me. I was wondering if anyone could give me formulas along with step by step on how to do it, whats going on, and how to put it in calculator! Thanks.