Which type of specialist should i make an appointment to see for back pain together with knee pain/leg weakness and sensitive skin/burning sensation in back/hip/groin area. ?

Back and knee pain : Your back problems may cause or contribute to nerve inflammation which causes leg weakness/knee pain and skin burning. I can not be sure about this hypothesis without an examination. I suggest that a doctor of physical medicine and rehabilitation can understand this from a neurological and functional point of view. There can be other possibilities, so I would first ask your primary care doctor.

See a spine orthopic: First see your primary physician who will treat you for other symptoms and will also refer you to a Spine Orthopedic Specialist for back pain