Welcome!
May I suggest you start by reading the articles on
the home page of this site, left hand column? Lots of excellent info on gear selection there, and some good gear lists. Especially with packs and shoes, the most important aspects are fit, fit, and fit, which vary considerably with each individual--comfort is more important than brand names. Be sure to heed the advice about buying your pack last, after you've bought your other gear--the pack has to fit your gear and be comfortable for you with your specific gear loaded in it (two of the 3 "fits"
I mentioned).
Ten years ago I updated much of my gear (due to age and injury I could no longer carry the heavy gear I had from the 1980's) using the "7 day, 27 lb. gear list" as a model. I didn't pay a lot of attention to specific gear brands or models, but rather to the generic descriptions and item weights.
Be sure to read phat's sticky post at the beginning of this Backcountry Beginners forum branch.
You can do the gear on the cheap to start out; here's a freshly published
$300 Gear Challenge Be sure to read the notes after the list for some highly recommended alternatives and other references.
Used gear is another way to save when starting out. So is renting or borrowing gear until you have a better idea what works specifically for you.
What I don't recommend is putting yourself in the hands of a big outdoor store like REI to get everything at once. I've found (the hard way) that most of their staff is not nearly as knowledgeable as they advertise, unless you get really lucky. You'll end up with a maxed-out credit card and so much unnecessary and/or overweight gear that after the first mile on the trail you'll say "never again!" I'm not saying don't go there; just do your research first and buy judiciously. I never shop at REI without my electronic postage scale in my purse. Drives the staff nuts and thus automatically gives me the upper hand!
There's an encylopedic reference to modern materials and gear on
Mark Verber's website. Not all of it has been updated recently, but most of it is pretty good. You probably don't want to start out with the very newest cutting edge stuff (too many $$$$!) anyway!