First timer

We can help you out. First, of the 12'x16' space, will you have plants under that entire space or is that the size of the room and the grow space is smaller? One of the first things that you should plan and set up is a ventilation system. Ventilation is extremely important when growing indoors. The lights you use will generate heat and a ventilation system will exhaust that heat from the grow space. While exhausting air out, fresh air that is cooler will be pulled in. You should have an intake vent for air to come into the space and an exhaust vent for air to leave the space. Here is a video i made a verrrry long time ago (so excuse the quality) which explains intake and exhaust. I break it down for beginners. It also talks about some of the equipment you may need such as AC, heater, humidifier, and dehumidifer. https://www.theweedtube.com/video/optional-grow-equipment-to-balance-environment---do-you-need-it-or-not--29614 After that we can talk lighting, fans, etc.

For that size room, an 8" ventilation system would probably be best. Here is what I recommend: Inline fan- https://amzn.to/368ISPK Carbon filter- https://amzn.to/2WfTgkm Duct- https://amzn.to/2Jn7BGe