When we camp we don't go too far away, that way if the weather turns, or someone is ill, you can just pack up and go home.
Try to take just the basics, Food, Shelter, Warmth is all we need! Tie hair up and don't worry about washing it. I find camping a wonderful excuse to have a weekend without giving a damn how I look or smell .
I would invest in a decent tent though, it's something you can use over and over again, and go one size bigger so you have room to breathe in there.
I don't actually own a tent, we usually just gate-crash friends/family's tents (I have a big family and we all go together). But this year we're getting our own car so we are thinking of getting a pop-up tent. You can get good quality 4 man tents that pop-up, designed for use at music festivals, by drunk teenagers, so should take the stress out of putting the damn thing up.
I will also suggest a picnic blanket with a waterproof back, plastic plates and cutlery, one of those gas cooker thingys, warm jumper (even in the middle of summer it will be cold at night), waterproofs, bottled water, teabags, beer and as many sandwitches as you can fit in your car! Suncream.