I'm new too, so I don't really understand, but I would advise you to buy altcoins that have good potential to promise a good future. actually a lot of good coins, it depends on your taste. Coins Ethereum, EOS, and Cardano are also good coins, if you wait for the price of coins to rise high you can get big profits, I'm sure Ethereum coins in the future will grow better and profitable.
Let's make it simple mate, it depends on your amount how much you want to invest. Ripple, Neo, ada, Ltc are also profitable. For how much time you want to hold? For Short term or long term? If you want to invest for long term then there are some coins which will give you profit.