Not sure what you mean as far as covering the window for temperature. Or why there is a man hole in your closet?
You have space to do lots of different options, depends on your goals.
If the house is lived in and not in the artic then getting heat out is more likely a concern than keeping heat in.
Blocking light from both directions is a good idea.
What you need is a place to vent heat and a place to allow air in to replace the air out.
Lights.
Ventilation equipment.
Filter to remove smell.
Air circulation (oscillating fans)
Thermometer/humidistat.[/QUOT
The goal is to get the right quantity without jeopardizing the quality. As far as growing complete newbie.
the Man hole in the closet exit to out door been here before I brought the house. I’m using that area to run the filters