Made Btc selling osrs gold

So I have a little story for all of you when I was a kid I played a game called RuneScape I sold the virtual currency in the game and kept getting charged back on PayPal so I decided to find an alternative to prevent that I found bitcoin and it changed my life currently been holding for over 8 years sold some to a Btc atm a while back but held most of it now I’m in a big of a predicament as I don’t know how to go about cashing it out when it goes up how do I tell Uncle Sam how I obtained it everyone told me I was dumb for holding it all these years but as a kid i understood the simplicity and benefits of this currency across all financial categories