This is great advice. And back to my tent (Seedhouse SL2), I have to say that while I love it as a one person tent, do not try to fit two people inside. You will be very cramped.As mentioned above, don't believe tent makers. In other words, don't try to get two into a two man tent- bump it up to a three man. Tent headspace- this measurement only works if your head comes to a point matching the peak of your tent.
Also, if you have anyplace near you that rents equipment, rent a tent your first few times out. If it turns out that camping is not for you, the tent is the only expensive piece of gear that can't really be used for anything else. A good sleeping bag will come in handy forever.
I almost forgot, give a lot of thought to your food. Especially when you're learning all this stuff at once, you want food prep to be simple while having a meal you're happy to eat. And carry in your pack (cans get real heavy real fast).