Crypto is very vast as you said.
Him advising you to buy bitcoin was a prof that he was after his own pocket. I for one don’t advise anyone on what coins to buy. Instead I will give you a list and tell you the story behind them.

Also,
I’d rather get a coin that I can buy it’s whole number than fractions. My advice to you is to go learn technical analysis because crypto still has a long way to go and we have barely scratched the surface.

Painful experience though. Money makes people do crazy things