Trying makeup...

I am trying to teach myself how to put on makeup. I feel so late that it seems like something you should know how to do as a teenager but I was never taught how to put it on and to know what to buy. The one thing that was hard for me to figure out is the foundation and concealer. Its hard to know which shade is the right one. The only makeup that I know how to put on is mascara and eye shadow. I'm trying to watch Youtube videos to learn and I have tried a couple of times and it just doesn't look right. The girls in the videos makeup look natural and I'm trying to get to where it doesn't look like I don't have makeup on and right now it is looking like I put too much on. I'm going to keep trying until I can get as good as the girls in the videos. Hopefully it won't take forever to master.