Since the car will be issued in your name under the Motability Car Scheme, you are therefore allowed to learn to drive in the car. You should however be displaying 'L' plates and be supervised at all times. Supervisor must be over 21 and have held full driving licence for over 3 years. It is recommended that you take driving lessons with a qualified instructor on top of private driving practice.
If you're going to be nominated on the policy, that is, if you're not the disabled person registering for the mobility car, then you must be 21 or over if you have a provisional licence and want to learn to drive in the car.
There can only be one young driver (under 21) on the policy. It can either be the person receiving the Disability Living Allowance (DLA) or someone else who's been named as an additional driver.
Only 2 drivers can be put on the policy. A third person can be added but there's a charge for this.
Drivers under 25 are only allowed to drive cars in the car insurance groups 1-16 not exceeding 115BHP (Brake Horse Power).