Hi dear friend
Most common cause of weakness and restlessness in legs no or less physical activity and strength.
I would recommend you to start exercising regulary, take proper diet, add supplements if required.
Rarely at your age certain medical conditions mught cause the same proble, you should seek a consultationfor the same.
Next Steps
Start proper physical activity and diet
Health Tips
Be gradual when step up your exercises, always do warm up for atleast 15 mins, be regular.