Help - vibrations from front end on new 14s not there with the 13s on

Jack the car up and spin the wheel watch and see if the rim is running true, if it is and the tire has run out the tires are no good.
If the rim has run out you will need to check if the rims are bent, that it fits the hub,mounting surfaces are clean ,that the correct lug nuts are being used.
If the rim are the multi fit (slotted lug nut hole) their real hard to get to run true. You can get hub centering rings to help with this.