forza horizon 3 newbie question?

So I'm thinking about buying forza horizon 3 in the next few days, but it's already been out for a while, am I going to be totally left behind and is it even worth getting?

I feel like all these people are going to have nicer cars and more mods and it will make it impossible for me to win a race.

Also, what kind of racing is it? All I have really seen on youtube is just short random clips but most is just driving around in free roam with friends. If I don't have friends online will I still be able to race people? Are their racing lobbies like in other games, or do I just have to find someone to race.

The game looks awesome, I just really dont know how it works and don't want to spend money on it if I'm going to get left behind. Thoughts, any help? Thank you.