You'll most likely need a fan to exhaust but with small lights you can let your intake be passive. If using a cabinet you're gonna need to put in light traps at the exhaust and intake. Put the exhaust near the top and the passive intake at the bottom. You'll need to exchange the inner air with the outer air cause the plants will deplete the CO2 levels which need to be replaced. For light traps you can use pvc tubing bent at a right angle.