board game arena (BGA) is affordable (even the paid plan which does not allow same IP address, but 1 computer on VPN bypasses that) and has a bunch of games to try. I used to play on BGA a lot with my non-gamer then-girlfriend when we were long distance and found a bunch of games.

The easier coop ones on BGA I found were: Hanabi, the Crew, Forbidden Island. The coop ones that I found outside of coop games were Pandemic and Flash Point.