Long term VS short Term

Hi, I have two questions. First, I acquired crypto currency in 2020 but only sold UNi for about $1500 gain on Coinbase pro. I never received anything from Coinbase pro. Do I need to file and declare? Second question, I usually transfer my assets from wallet to coinbase for sale. When I import report it will show it as short term sale with what basis? How does the IRS confirm that? Also, if I add my wallet transactions there is always a mismatch since I acquire a number of coins and sell less.