Well Congrats on becoming a Lauder family member!
I work for Estee Lauder through Macy's as well. I have seen maybe one male Estee Beauty Advisor. You'll definitely be one of the rare ones.
As for uniform, you're joining as Estee is in the process of changing their uniforms (again) which honestly, thank goodness, because the current ones are not very flattering at all, for the women anyway. More than likely you will be provided with a uniform. It's pretty standard for the males though, so you shouldn't worry about that
I will say that Estee Lauder provides GREAT training for their BA's. But it's a VERY demanding & competitive line. Personally, I think you're real lucky to be one of the very few males, because women tend to gravitate more to male BA's than women. They don't feel like they have to measure up (so to speak) with the guys than they do with the gals. After you learn the products, the techniques, etc., you'll be sought out and will have a great clientele base.
Good luck!