Some good replies here. The missus was brought up with caravans, so she decided about 5/6 years ago that we should have one, and so we did (against my better judgement). My one caveat was that I would never empty the toilet (she says it’s not too bad).
Top tip that I would offer is to go to a caravan show, and whilst this may seem like one of the Seven Circles of Hell, and you will be amongst the youngest there, it’s a really good way of looking at lots of layouts and seeing which one(s) is right for you.
Our first caravan had a pair of bunks, whilst our more recent one has a fixed bed for us, and the kids either make up the front bed for themselves (no work for us) or sleep in the awning. We do have a decent bathroom because we are plumbed into mains water and drainage on holiday in France, and we use our own shower.
Re: car – there are some fairly light caravans out there to suit most cars. Don’t exceed 85% of the car’s weight, and look out for the noseweight (buy a gauge). The car we use is fairly strong, and we don’t find ourselves holding too many people up. Some modern caravans also have a kind of stability control that engages the brakes selectively to prevent snaking.
Good luck. Once you get over the embarrassment, it’s a pretty nice way of being on holiday with bikes, wetsuits, body boards etc. Our kids are now old enough to disappear with walkie talkies and roam the campsites with friends.
EDIT: Didn’t see the LR Discovery comment.