Rule number 1:
Enjoy yourself!
They rarely come out how you'd hoped, (often at the beginning they look like they've been overrun by glue-gun wielding cossacks) but as long as you had fun making it then that doesn't really matter. The next one you make will usually be better... usually.
Be reassured that I hadn't touched a kit for nearly 20 years but after 6 months or so of plastic disasters I began churning out stuff I'm sometimes quite pleased with, the learning curve can be really satisfying, and you can learn a surprising amount about that vehicle in the process:
(Oh yeah, actual advice: use acrylic/water-based paints to begin with.
Far less hassle than oil/enamels. And be sure to check out
Missing Lynx.)
Cheers (and good luck!),
Adam.