Well done Pfft!
Good, innit? 
McNo, 40ml in total sounds like a good amount to start with. As we're all discovering, most places do very fast delivery and you have a local shop too if you find yourself running low.
Weelady, 3.6% (AKA 36mg) is the highest strength recommended for vaping. Any higher than that is really intended to be diluted down before use. Most smokers when they first switch seem to do OK on 18mg, some need 24mg and a few 36mg. Some cut down once they're safely off the fags, others never do. Nicotine on its own is quite similar to caffeine in terms of toxicity. Interesting reading here and here.