The best alternative coins to buy are Litecoin and Xrp.
The reason why these two coins are the choice is because these two coins are really good fundamentally, have real functions, community and will soon be ETFed.
If you want to buy I think you can choose $LTC because the price is not too far up.
LTC Price will 200$+ Xrp Price will 4$+
If you want to learn how good these two coins are, you can do your own research from the best sources.