A good way to make your choice consider these things
Platform viability
Developer activity
Communty avtivity (is the community active and using the platform)
Your budget (i suggest spending on 2% of your holdings on an investment till you feel good)
Whitepaper
Exchange listings (is it easy to buy, does it have good volume?)
ALWAYS BUY DURING A DIP NOT WHEN ITS RUNNING UP YOU WILL BE MAD
There are many other criteria you can us but these will at least help you get started and build up your understanding of the cryptoverse