You would have to buy the suitable controller and bind it, which would require a little research. Also a battery charger - not too expensive.
The more sophisticated models e.g. DJI do require an app and to do most things you need a (free) account with them.
Used models can be bought and sold, there doesn't seem to be any obstacle to changing owner.

Generally they are tougher than they look and minor crashes might cause little or no damage.
However if they have been wet for long outside careful drying is required before restarting.
But again some have been retrieved (e.g. after harvest) weeks later and still worked normally with a bit of TLC
Clean rainwater is not instant death to electronics, especialy if it had switched off before getting wet.