I’d have probably replaced both calipers if I discovered the boot on one was torn as part of doing the brake job. Bleeding the ABS varies car to car. It’s usually best to do it with the aid of the factory scan tool so the solenoids can be cycled as the bleeding is being done. Best to consult your factory service manual for what’s required and what’s just “convenient” but not a strict requirement. It’s important when pushing the caliper pistons back in so the new pads will fit to release the fluid pressure by loosening the bleeding valve on the caliper first. Otherwise you risk pushing brake fluid residing in the brake line back into the ABS, which can sometimes cause problems you don’t want. If you have any doubt at all, good idea to consult a shop to verify your work.