Im a sever and i have sharp pain in right knuckle. the more i use the more it hurts. i can splint my finger and the pain lightens up. what can i do?

Overuse injury: Could be a sprain or any of various kinds of overuse injuries, etc. Best way to get it to settle down is to use it as little as possible - wear a splint, use your other hand when you can, and remember price: protect, rest, ice, compress, elevate. Anti-inflammatories such as Ibuprofen (up to 800mg, or 4 over-the-counter tablets or capsules, 3x/day, take with food) can also prevent & relieve pain.

Hand pain: When people say knuckle they are typically referring to the so-called metacarpo-phalangeal joint (mcp) i.E the one people use when they punch. But other joints of the hand can also be painful. One would need to know more of the history, and especially if there is any history of trauma which would be on the top of the list. A good history and exam will help. Good luck.

Which knuckle : This question would be a lot easier to answer if we knew the specific finger and joint involved. At your age I do not suspect osteoarthritis. Probably just repetitive stress from how you hold plates when serving.