The first time I went she explained the HD "shape" and checked I understood and that that was ok (basically it's about where the arch goes). Then she asked about colour (which will depend on your hair colour and how dark you want them to be - you can always start lighter then go darker if needed). As she was plucking she was telling me about my brows and where they need more plucking or more growth.
I would say, the tint washes off fairly quickly, so I actually like mine a bit too dark to start with. And, the first time there is a lot of plucking to get the shape.
I love my HD brows, I have to stop myself going fortnightly to get them tidied up.
They really don't go too far. It's a process and should take a few visits to get to where you want to be. I'm nearing 50 and go every 6 weeks and my eyebrows just look normal and well groomed. You will be fine - honest!
The tint is for the hairs - I assumed it would colour the skin too, but it doesn't.
Honestly, before the first time I went, I mentioned it to some friends who looked shocked and asked what's wrong with my brows; afterwards I saw them and they were amazed at how much better they looked (and went to get their own done!)