I car camp a couple times a year. If your SO isn't much for roughing it, go to a campground with some creature comforts like toilets and showers. KOA's aer very nice. Otherwise, I prefer to not be in a campground.
Water: Bring alot, I usually go through about 5-10 gallons in 2 days for 2-3 people. A little more if I've got a Solar Shower (cheap, and great for washing up).
Stuff to do: camping is boring unless you're just a patient person. Hiking, biking, fishing are the reasons I go camping. Go camping for the recreation, not for the camping.
Tent: Buy a bigger one then you think you need. Its nice to be able to stand up and change clothes in it. Also, set it up in your backyard at least once, so you're familiar with it. Doing it in the dark when you've not done it before can be a crappy start to a trip.
Lantern: I've got a Coleman that auto-lights. No matches required. Always have spare mantles.
Food: I also do most of my food prep at camp so I've got something to do, unless its a fishing trip
Site selection: Not too close to the crappers. Not too close to any trashcans. Next to a babbling brook is nice, but remember, it can drop the night time temp by a few degrees...if you're at 8,000' and its 30* at night...well you get it...
Wildlife: If you're in Bear country, learn the appropriate countermeasures (like not eating where you sleep, and not wearing cooking clothes to bed). Don't leave food out anywhere (Racoons can ruin a trip fast). Don't feed the wildlife.
Memories: Take lots of pictures!
Organization: Everything I take goes into those rubbermaid totes.
Gear: Don't scrimp on your gear. That said, you can find things like cookware at the thrift stores, sometimes you'll be surprised what you find.
People: I like to camp where there isn't alot of peole, but sometimes it can't be avoided. Be friendly and courteous!
Alchohol: I prefer beer, and generally avoid glass while camping, I'd hate to ruin a campsite by breaking a bottle on it.
If you've got a truck or SUV, consider buying a used pop-up camper.
Lots of other good advice in the previous posts.
Have fun!