If you haven't already found them, there are lots of excellent articles for beginners and on gear selection listed in the left-hand column of http://www.backpacking.net/, the home page of this site.

Another good site for gear selection is Mark Verber's website. Lots of ideas for gear, from the latest technology (not all of which is expensive) to low-budget alternatives.

While I have to admit that I have a $300 tent and a $325 sleeping bag, you certainly don't have to spend that much to be lightweight and comfortable! Some folks like to collect the latest and lightest gear that comes out--that's their hobby! That not only keeps the small manufacturers (many of whom work out of their basements or garages) who make the really innovative gear going, but puts a lot of excellent used lightweight gear on the market for those of us with lower budgets! If you want a solo tent, especially watch for used Tarptent Contrails right now--a lot of folk who have had them have switched over to Tarptent's new Moment. There's nothing wrong with the Contrail, it's just a lot of people wanting the newest thing!

I agree with the others here that your leaky tent is the first thing that absolutely must be replaced, for your own safety! Your pack may have to go too unless lightening your load solves the soreness problem (try that first). Pack fit is almost as individual as shoe fit, and it's vital that both be comfortable!

If you're going to be in the high altitude areas of the Rockies, where it can and often does freeze at night any time during the summer, the Campmor sleeping bag might not be warm enough--it's more like a 30* bag than a 20* bag. (Most sleeping bag ratings, especially for the less expensive ones, are purely fictional.) You may be able to get by with wearing your insulating clothing inside and with a good insulating pad underneath (the last being highly important). Elsewhere, the Campmor bag will be fine unless you're winter camping. Below 40*F, you either must supplement your blow-up air mattress with a closed cell foam pad, switch to foam alone or get an air pad that has insulation in it.