Start with a simple weighted ball program. Driveline used to have a free program on line.
The Jaeger long toss is also an option.
Catcher son warms up with a 6 or 7 oz ball out to about 60-70' and then swaps to a standard ball and moves out to long toss. As a pitcher, he threw mid to upper 80's.
Arm velocity as a catcher is important but it's less than half of your pop time. Adding a few miles per hour will not "significantly" decrease your pop time.
Arm velocity can make you stand out and pass the eye test.