Coloradcatt,
My

Cheddarbob gave you good advice. It is very tempting to want to rapidly acquire orchids, especially with a greenhouse. Please don't!
Watch your environment closely. Note in writing your sun hours, strength, High and low temps and any microcosms.
Then select a species to grow and learn to master it. Spread out from there.
All a greenhouse will do for you at this novice stage, is enable you to kill plants quicker. I often give plants away but like animals, it's a "free to
good home scenario.
It takes a humble person to listen to advise. I've killed my share and I'm hoping to prevent you from doing the same.