It's a simulator.
For this reason, there's no storyline or other stuff here - you just select racing series, car, track and go driving, so you don't have to worry about any sexutality/violence that can be found in other games.
Also, driver's don't get injured and you can't even hit a mechanic - you'll just pass right through him like a ghost.
So yeah, it's perfectly safe.
But for the same reason it's preferable (but not strictly necessary) to have a reasonable steering wheel, drive using cockpit view or roof camera only, and there is no street racing or regular traffic here - just racing circuits. There are lots of addons of course (cars and tracks), but generally it's all about the professional side of racing.
Additionally - the only way to play multiplayer is through network - be it local or internet, but there is no split screen mode for two players - you'll need to connect two computers if you want to race each other.