Having leg pain on standing walking and pain in hand/shoulder while typing if I sit long thn back pain wt cud be this?

Multiple things. This could be multiple different things, including separate issues. This could be a combo of lumbar and lower cervical radiculitis, +/- carpal tunnel syndrome +/- meralgia parasthetica. Hard to tell without more history. Discuss with your physician because you may need large workup, including ruling out ms. Until then focus on core strengthening and correcting ergonomics.