You need to be extra careful with airdrop coins, especially those with desktop wallets. They can be infected with viruses / keyloggers in an attempt to steal your wallet keys. That's not always the case but worth making a point.
Ditto. Make sure you invest in a hardware wallet if you are not the most savy computer wiz. It's affordable and can prevent a lot of heartache down the road. Check my "thread" history for more thorough explanation why you should buy a hardware wallet. I hate reading threads about people getting robbed of their hard-earned coins.
Edit: here is the thread - https://bitcointalk.org/index.php?topic=2270804.msg23018577#msg23018577