How/where can I learn to day trade?
Honestly? You can learn every day, with every trade.
There's not much of a secret to it. You're trying to buy low and sell high. To do that you need to get all the information possible to understand if the current price is low or high. Beyond that, practice makes perfect.
The only other advice I can provide is to focus on 1 or 2 cryptocurrencies. Keep your scope of interest narrow, but deep.