One good idea with things like this is to only concentrate on one type of thing at a time-- rather than trying to do it all at once. Maybe learn all about bras, then shop for them, find out your size and what you like. After you've got bras down, advance to some other clothing item. Eventually you'll have it all down.
This method works especially well with makeup, too. Rather than trying to get everything and do your entire face right at once, start with, say, foundation and a beard cover. Practice and try products until you're doing it satisfactorily. After that, move on to, say, eyebrow pencils. Work you way through these things gradually.