Disc Brakes may require some adjustment from time to time, as with any other style of braking system. The steps here are as follows:
First - Ensure the rotor itself (round part) is straight when the wheel is spinning
Second - Make sure the caliper is aligned with the rotor
Third - We want adequate clearance between the pads and the rotor
For *Mechanical Disc* brakes - take a look at the following tutorial -> https://www.parktool.com/blog/repair-help/mechanical-disc-brake-alignment
For *Hydraulic Disc brakes* - click the link provided -> https://www.parktool.com/blog/repair-help/hydraulic-disc-brake-alignment
This is a standard bicycle repair procedure any bicycle shop can help with. If you’re unable to complete this adjustment yourself, feel free to swing by any local bike shop and they can certainly help.