Yes you must report it. The exchange is giving information to the IRS on your transactions. You do this even if they don't send you a tax form. Don't be the guy that gets audited and busted over crypto.
You need the date you bought it and for how much, you need the date you sold it and for how much.
Say on April 1st you bought $5,000 worth...….. On April 15th you sold what you bought for $5,200 you claim $200
Let's use same example but instead of a return of $5,200 you only get $4,800 you claim a loss for $200.
The total is net proceeds after fees so whatever the end amount is, that's what you sold for.
If you bought and sold it within a year, it's a short term gain/loss, if you held it for more than a year and sold, it's a long term gain/loss.
https://www.coinbase.com/learn/tips-and-tutorials/crypto-and-bitcoin-taxes-US should help get you in the right direction.