I bought the growers choice controller and it has port a and port b that each port can control up to 100 lights but there’s only 1 plug on the controller
Did you read the manual? Because I feel like you didn't read the manual.
Because:
Is what the manual says. Line out from the controller into the 'A' port on the light. Line out from the 'B' port on the light into your next light's 'A' port. Repeat for however many lights. I'd pretty much guarantee the A and B ports are parallel wired as suspected.