Many things can cause your problem
Any one or combination of the following factors can cause steering wheel vibration:
(1) Tires out of balance
(2) Tires/rims out of round
(3) Alignment due
(4) Tie rod ends worn out
(5) Tie rods loose
(6) Guide rods loose
(7) Guide rod mounts torn
(1)-(3) need to be done in shops
(4)-(7) can be done by DIY