PIMETA v2 or CmoyBB as first project?

If you've never soldered before, get your self some strip board and cheap resistors from ebay and practice soldering them following the various guides around. a CMOY is a good, inexpensive place to start and you get something out it. Once you're comfortable, or at least have learned some lessons from the build you could move on to more expensive builds. While I think the PIMETA would be fine for a first build, there is nothing like having a bit more confidence from easier project.

Just take your time, buy good tools (temperature controlled solder station is useful, 63/37 lead/tin solder is nice, find a tip you're comfortable with, get braid and a sucker, side cutters, a multimeter, take your time and follow the instructions, measure the DC at the output and test on cheap headphones first). Once you've got a working project under your belt the skys the limit.  Just take your time (I think I've made that point :) ) and double check everything!

Which ever you choose, have fun :D

To avoid blowing the drivers measure the DC between each of the output channels and ground with the volume all the way down. You don't want more than a few mV, especially into sensitive headphones. Still a good idea to use someone elses headphones for your first run

Have fun!