Congrats! Its a fun four years!
For your question, you're allowed to wear make up that follows AR 670-1 and the cadet equivalent (uniform regulations) while in uniform as a cadet. The amount of makeup will differ depending on the uniform (i.e. combat uniform vs class uniform).
I don't remember anything about plebes having a ban on make up; my roommate was a rabble rouser (cheerleader) and I have very vivid memories of her putting her makeup every morning, hoarding the sink first semester, that it definitely wasn't a thing in my company although potentially could be restricted dependent on company as a plebe. There can be random things that some companies will be more strict on than others. Another example would be my company didn't care about plebes having video game systems in their rooms while other places banned them for a semester or outright all plebe year. Just dependent on the company's policies. As an upperclassmen, its just what the regulations require.
There weren't any stigmas around makeup assuming you're talking about during the academic year. You won't see as much of it as you might at USAFA (I only make that comment because it was something that stuck out to me very much over the four years with interactions with the folks at both institutions), but makeup is one of those things that many women will wear because its fun and a reminder that they're girls (especially when wearing those fantastic gray trousers). If you are wearing makeup in regs and acting in a way that people aren't questioning your behavior (good at what you do, physically fit, etc.) wearing make up won't call negative attention to you. Emphasis on wearing makeup in regs and acting professionally though. If you wander outside of those two realms, it can start to attract unwanted attention. In terms of field, yes, that can draw some looks if you're putting makeup on.
Now, if you have the time/energy to put on the same amount of makeup as you may/may not today is a totally different story. Life gets really busy, very quickly. Definitely a great time though as an overall experience. Wishing you the best of luck.
