WW – Beginners: who has tips?!

Hi guys, I decided to buy a WW. Unfortunately, this matter is totally new to me. Which things do I have to pay special attention to? My budget is 5000-600€. Do you get something reasonable there? We have 3 small children (1, 2 and 4 years old), are therefore 5. What would be nice if it would be suitable for winter to go skiing in 1-2 years. I also drive a Sharan with 120 HP. Please give me tips in the following areas : Axles (a Can ter meant, only no 2 axles, because you can not “pull” it) length heating / insulation etc. Thanks to all “old” rabbits! teachingtimo