First off I will remind you this, the counter/store artists are still sales people. It is a retail sales job with weekend hours, customers who can test your patience, and hard work. You can move up in the company to be a trainer as an artist, but again its hard work because all the girls want to get there. But if you truly do want to this, then you should do it. I just want it clear that the job is more than makeup. A lot girls want to work for MAC until they get it, then realize it is still retail.
Just know many artists do not make it their first time, or even second time. My regional trainer didn't make it her first time, nor did my manager. But don't be discouraged if you don't. Call the person, ask for feedback so you can improve. THey will remember you for doing this. Go to the special events for collections and get your makeup done. Explain to the girl your goal, and ask her to explain the techniques she's using so you can learn. Also if you have a friend willing to do this, have an artist do your friend and let you watch and listen to the artist so you can observe. ANd of course practice on all your friends to get comfortable. Doing makeup on others is very different than on someone else. Take pictures of your work, post them and get constructive criticism. It's not fun, but criticism is your biggest asset. It allows you to improve. It's also a way for you to see your potential abilities if you continue practicing.
I've never taken a class outside of MAC for training, so I can't help there. But anything should be fine. MAC doesn't have a blacklist, your demo is your chance to show your skills.
Finally, I hope you don't worry too much about what others say about your goals and dreams. If you want this, go for it. It's your life to live, not theirs.
Good Luck!
