I would like to buy 10 crypto currencies ($100~$150) each and leave it for a long period. What are the pros/cons of such approach? Some things I can think of

• Coins disappear with time and some might be erased over time...?
• Holding them?
• Creating a paper wallet for each (I do not want it to be in an exchange, I do not trust them)?
• Transaction fees might be too high?

I don't know what I don't know, so I am not sure what to be careful of, so I am asking from your experience.

Thanks!