Wise choice for your first Forza .
There is many ways you can play Forza...
I'll list out a few which I know;
1. Cruising.
2. Drifting.
3. Drag racing.
4. Normal racing.
And loads more.
You can do anything you want which involves a track and a car .
I'd advise you to finish the Career, then move onto the things listed above. Main point being is that you would need cash. You can mod your credits but it'll give you a chance to get banned so I advise not to do it unless you wan't to do it.
If this is your first driving game then it'll give you some instructions on the 1st race. You'll get to know it pretty fast and you'll find that it's a very good game to play.
As you gain driver levels you unlock cars which you get to choose. There are 50 levels maximum I think. (I haven't played F3 in ages).


Hope this helped you, but you can always check YouTube for advice etcetera.

Any questions PM me.

~Tandeming.

I suggest you take up Drifting in Forza, it's fun and has a bigger community. Or maybe take up designing.
Also, if you do decide to mod your credits on Forza 3, you will not get banned, hardly anyone gets banned on Forza 3.
If you need anymore help, just PM me.

ill help u send me a fr request