New disc brake pads and rotors have not yet developed their normal braking feel. During bedding in, a small amount of pad material transfers evenly to the rotor. This helps the brake deliver more consistent performance with less unwanted noise.
Use a safe area away from traffic. Accelerate and slow down under control several times without locking a wheel, allowing the bicycle to roll again between each braking effort. Follow the brake manufacturer’s specific sequence for the model fitted to your bicycle.
Keep oil and dirty fingers away from the braking surfaces of the rotor and pads. If the brakes still feel weak, vibrate or work unevenly after bedding in, have a bicycle shop inspect them before riding in traffic.