Keep at it, and when in doubt, just ask. You'll get some jerks, but most people are happy to make the fights as smooth as possible. I very often see "First time tanking, anything I need to know?", and if there is someone either says something, or the bad ones just leave (jokes on them, it's easy to get a heal/dps replace, tank..not so much, and they get penalty, so you can have a chuckle at them).

You'll be getting commendations all the time (that's the point of playing isn't it?....right?)