Welcome to Epic.
I am about your age and have been wearing a helmet for 15 years or so.
Yes they are warm but sometimes I do wear a thin balaclava under it which also covers my chin when needed. I don't think a brim does anything but style so buy on your preference.
Here is some first time helmet advice:
Your helmet like your boots needs to fit snug but not tight. Too loose and it won't stay put. When you have it on and strapped, try to slide it back and forth on your head with a gentle motion, if it slides too easily it will be too big and of no use in a fall as it will not stay put. You want to feel the helmet move your forehead skin a little. Nice and snug but not too tight.
Look for a helmet that has built in size adjusters to fine tune the fit.
Look for a helmet with adjustable ventilation via a slide that opens vents vs the plugs that you have to pull out and store in a pocket and eventually loose.
You can also find helmets that come with speakers for music and bluetooth for connectivity.
It might take a day or two to get use to them, but once you do, you will find that a good helmet is very comfortable and you won't feel comfortable skiing without it.