Question about selling BTC

Hodler here since 2021, never sold a sat. Life changes may drive the need to sell a little….

So my Q is: I first bought on an exchange, will I need to sell exact amounts to keep up with the tax reporting? So for example, let’s say I bought 0.2 BTC at $40,000. I would then need to sell that exact amount at $59,xxx? Apologies for the nube question, thanks in advance