Firstly you yave to learn about technical analysis because this is will be basic of day trading. Use time frame minimum 1 hours and learn price action of crypto by understanding chart pattern and candlestick pattern. You should understand about support and resistance level to decide entry buy and sell. Other important thing you have to set percentace of take profit and stop loss in every trade.
You can only be successful in day trading once you will go for with all your heart and mind. You need to be sure that you want to do it yourself and that you are ready to learn anything which you need to learn honestly. It takes a lot of efforts for anyone to learn those things but once you learn such things, then making of money is just a piece of cake and that all your efforts will then bring a sweet fruit for you.