To earn money in crypto, the basic things you're looking for is to buy low and to sell high. Thigh will mean buying certain coins like the Bitcoin and the alt coins like the Ethereum and the likes. Before setting out to buying any coin, you need to sit and look out for the best trading strategies that suits you the most.
After youust have gotten that right, then you will have to back-test it on the past price history and see if it will work well for you now. Whichever one yeilds the most profit and has the lesser risk should suit you the most.
After getting the best trading strategies that suits you the most, the next thing will be risk management; here you're going to manage your portfolio. That's when you're going to decide how and when you're going to be taking your profits, weather to buy and sell, and also ensure that youe keep your details as private as possible, ensure that you're security conscious and don't click on suspicious links, as scammers try all they can to steal people's assets. Stay safe out there.