Some good advice here already. Congrats on your great ride! YAY!
1) I used to get sore between my thumb and index finger, and for the first couple of years I took to lubing the area with neosporin before putting on my gloves. Made all the difference, and now I never need it anymore. I guess I just out-grew the problem, or got a callus, or whatever.
2) You can get shims to make your 105 brakes easier to reach. In fact, mine are double-shimmed. That is not ideal for me, and when I get a new bike, I will get short reach shifters and a woman's bar. But, for now, for this bike, for my budget, it works OK.
"The best rides are the ones where you bite off much more than you can chew, and live through it." ~ Doug Bradbury