DLR does not have its own “camping” type resort. Here is what the DLR website says about parking!
$10.00 for Automobiles
$12.00 for Oversized vehicles, motor homes and tractors without trailers
$17.00 for Buses and tractors with trailers
Oversized vehicles include:
passenger vehicles with trailers
When visiting Disney’s California Adventure™ park or Disneyland® park, these vehicles are asked to use the main entrance of the Mickey & Friends parking structure, located off southbound Disneyland Drive and Ball Road. Be aware that the height limit of the Mickey & Friends parking structure is 13’10".
There are campgrounds/rv parks in other areas. I would check KOA’s website and see if they have any in the area.