Agreed.

Until you can get a good pack, camping in the backyard, or at a local state park campground, means you don't have to carry your pack in. Dayhikes are always fun, and you can come back to your house/campsite and practice using your gear and sleeping outside. Not a perfect solution, but a definite start.

Check in with a local college - many will have outdoor programs, and may even let you rent gear until you can get your own. Also check with a local backpacking shop; it may sponsor guided trips, even beginner trips, and rent or provide gear. That's a good way to get started, and if your group is like mine, you may even have a gear head who likes to try the latest and greatest, than passes on his lightly-used "rejects" to others in his group. I was out with such a group a couple of weeks ago, and saw a lot of familiar gear coming out of packs - some of the packs looked familiar, too.