Hi, Garda is about a 3,5 hour drive for us, so we visit quite a bit.
For caravans there are a lot of sites, but be warned, they cater to the Italian/German/Swiss German tourist, so in peak seasons prepare for organized entertainment galore, Birdy songs and Scnipp,schnapp Snappi - das Kleine Krokodil on repeat.
We stayed in the Altomincino Family Park at the bottom of the Lake in 2011, it's not on he water front, but it's easy together to Sirmione, which is a must do when you visit - the walled island is lovely to explore. The Gelateria and restaurant were great,pools were lovely but you couldn't park by your van.
We have stayed in one park in a static caravan ?200 euros for the week with a Lake View in Camping Piantelle. There was a lovely walk lakeside to Padenghi together the ferry. It had a basic restaurant, shop, pool and of course the entertainment. You could park by your van.
Both were very good standards of cleanliness. We booked both through Hotels.com. There are hundreds of parks around the lake to choose from. They get busy through July and August due to Swiss and Italian holidays.
If you want hotels there are lots to choose from at many different prices. In Salo, we stayed at the Il Duomo, right on the Lake front, it had a hot tub and rooms were really nice for 110 a night and breakfast.
We are currently looking for a property there in the Salo region, it's my favorite town. travelling up to Limone is beautiful too. A day can be spent hopping on and off the ferry/cat.
There are some theme parks Gardaland,Movieland and an aqua park attached. I didn't rate it much but ds loved it.