It's strictly multiplayer but it's also a PvE game and the community is generally pretty great at helping out new players. There isn't much toxicity in my 200ish hours of experience, come across the occasional troll that team kills but the host can boot people so they get kicked pretty fast. It is more fun with friends, but I probably have around half my playtime just playing with randoms and I always have a great time.

Definitely recommend giving it a shot!

Completely different game solo. Stealth is more viable and necessary. I prefer full squad, personally.