Now that I am several evolutions into this gear thing, I suggest the opposite of your plan - rent or borrow those things. Tent, pack and sleeping bag/pad are the most expensive and least objective items you will get. What works for you may be completely different than what works for anyone else.

You can buy inexpensive base layers, inexpensive rain gear, make your own stove and get a cheap pot - food for an overnight doesn't have to be some expensive freeze dried meal, a Subway sandwich works. You will want to not wear a lot of cotton if it's probable rain, but your first trips will likely be fair weather and short - you can get by with stuff you already have one or two times, if you've got synthetic or wool stuff already. Even hiking boots can wait if you have tennis shoes that fit and will be comfy for a few miles. This is all presuming that you follow other advice for newbies about keeping the miles shorter and going out for one night. Do an overnight or two before you go on those trips with your friends and you'll get some experience that will make them easier for you.

lowergear.com rents, so does REI, so do some other stores - our local outdoor store does. You can also rent bear canisters to keep out critters where necessary.