Hi Amy,
Welcome to Beach ownership! It will be an amazing source of fun and adventures for you family. The members of this forum provide an amazing source of knowledge and therefore answers to almost anything VW Camper related that you might need to know! There are plenty on here with more experiences than I but my top tips would be:
1) Get yourself some well shaped storage boxes. We have some WM boxes with clip on lids that store all pour essentials, stacked, when in the garage at home or in the van, but the beauty of them is that they will slide neatly under the van as soon as we get to site and will keep all the contents dry and everything is easily accessible. This also frees up the boot space under bed should you wish to store any valuable in there overnight (like a bag of body boards in our case) The VM boxes we have are 79cmx39cmx18cm You can get a lot of stuff in them!
2) Go with the flow! Don't overly rush out to buy accessories until you have done a few trips or some reading around this site (as there are many 'most useful / least useful' topics). That will mean you won't waste money on things you really don't need allowing you to buy the things you really will find useful.
3) We have created a diary of our adventures, no of trips, nights away, activities when there and when we research places to go, we make notes in it, things to do next time in that area etc. We have done 2 x 3 week trips to Europe where we had a decent plan of where we wanted to go and potential campsites to stay at, but pre-booked nothing as we wanted some degree of flexibility. Be bold! Planning a route that takes in attractions is definitely a fun part of the adventure too but freedom to vary the plan is just great... and the journey is part of the adventure!
Have fun
Ian