If it is a 12v it must be very small one. You can cut out all the electronics and wire the pump and fan and have a perfectly functioning unit.
Needs to be switched of on a timer every couple of hours to defrost.
I mostly use lumantec ballast one thing i have noticed they prefer lumantec bulbs. Growmaster start flickering.
More light output too with their own bulbs.
Yea time to repot. Size pot depends on how long you want to veg for.
Nip out the top of the plant and remove lowest leaves.
Use them lights for the first grow as your not worried about yields. first grow is not going to be much anyway.
Young leaves are easily damaged by light or/and water. Avoid getting the leaves wet with the lights on.
More patience and less fussing.:bigjoint:
Always check underneath leaves for bugs.