Formatting and full comprehensive sentences are your friend.
You need to know the thrust at the wheels.
Found from engine
torque * gear ratio * rolling radius.
This will give you the max force available at the wheels.
F = mg sin theta
Run for a range of theta, and you can find the max slope you can get up.
or rearrange or theta and work it out with arcsin (I dont know if you will have learnt that at 14)