If you are a newbie, start first by trading using BTC and USDT only. Learn how their price pattern work. Next add ETH in the list if you are already making profits. Learn how to play with the 3 crypto. This is the basic.
Wish I read this earlier ;-)
I myself now pick the main ones like BTC and ETH and invest small amounts in altcoins. Daytrading on exchanges can also payoff however is risky if BTC has anothed bump through the roof