The question on which blade to use varies... The best way to find out which blade is best is to order a razor blade sample pack (Westcoast shaving has a good one) and try them!
I started with the Parker 22R before all of these enablers here convinced me to look for vintage Slims and Fatboys. I think the 22R is unfairly maligned in the reviews section of this site. I found it to be perfectly fine for my "training", and, being a butterfly loader made it even better.
I agree with the others about trying the west coast sampler. I originally started with the 7 a.m. greens that came with it, which are very good starter blades--not too sharp, so they won't cut you to shreds, but can give you a reasonably good shave. Went on to Feathers, which feel wonderful bit ripped my face to shreds.
I would probably suggest you not go too "aggressive" if you're starting out. In your West Coast sampler pack, I might recommend starting with the Derbys, and then move through the Crystals and Red Personnas, and then leave the face-slashers like Astras and Feathers for last, wnen you've got your technique down.
thanks for all the advice! i've been checking out mantic's videos and now feel adequately prepared for my shave. unfortunately the razor isn't here yet