If your brakes are squeaky, the first step is to ride your bike at top speed, and firmly compress both brakes and come to a complete stop. Squeaky brakes are generally caused by a “glaze” that builds up on the rotors and pads, which can be removed by a few forceful stops. Humid days can also cause squeaking. If this does not solve the issue, you want to remove the brake pads and sand the braking surface with ~100 grit emery cloth or sandpaper to remove the glaze. You also want to clean the brake rotor with rubbing alcohol, acetone, or a similar solvent. After this, follow the brake adjustment procedures below.
For adjusting Mechanical Disc Brakes (cable) - check out the following tutorial:
https://www.parktool.com/blog/repair-help/mechanical-disc-brake-alignment
For adjusting Hydraulic Disc Brakes - check out the following tutorial:
https://www.parktool.com/blog/repair-help/hydraulic-disc-brake-alignment
If you’re still experiencing difficulty, any local bicycle shop can handle adjustment and parts replacement on any EVELO model.