First step is gonna be to set your throttle EPAs to their maximum. EPA = End Point Adjustment. It adjusts how much throttle/brake is applied or how far the steering servo turns. If the throttle EPAs aren't maxxed out, the ESC will never know where full throttle/brake is and it won't calibrate correctly.

Then calibrate the ESC to the radio. That will teach the ESC where the neutral point, full throttle and full brake points are.

Start there and see what happens.