Don't sweat it Tom, I didn't even know you had to use airbrush specific paint
. We'll get you going. Def check out the link posted by Gothrik above which will get you on track.
Probably the thing that people find hardest is getting your paint/ reducer/ air ratio right to get good flow. Until you get this it is hard to focus on technique, and its when you are more likely to get blockages. There is no magic recipe as there are too many variables, so when you get your paint spend some time experimenting to get Tha right. It might take a while, and can be a bit frustrating, but we can talk you through it. Just make sure your nozzle stays clean, I guess around 90% of issues can be linked to blocked or dirty nozzles. And if it looks clean, don't believe it
and clean again.
Regular printer paper is ok to practise on, but wont be ideal for more advanced stuff later. Many people use Bristol board, and schoellershammer 4 paper ot board.
If you just want to work on paper then popular brands are E'tac fx - many pros like, but a bit more pricey, which you can find at airbrushandpaint.com I think, Createx Illustration, a bit more readily available but I know is carried by smdesigns. Com-art, and Golden are also popular, and graphicair and custompaint.co.uk are other suppliers I've used.