This time of year you are best off to stay in the central and other parts of AZ...weather and temps up in the mts of the Mogollon Rim and the Flagstaff area can be cold and unpredictable... but there are lots of places in the Phx metro area and SoAZ to enjoy.
The Arizona State Park systems is well developed and you can make reservations...find state parks with camping here
. Recommended: Lost Dutch State Park near Apache Junction, Picacho Peak between Phx & Tucson, Catalina State Park in Tucson, Roper Lake State Park near Afford, AZ, Kartchner Cavern near Benson, AZ and Patagonia Lake State Park east of Nogales, also the state parks on the lower Colorado River... Buckskin Mt, River Island, Cattail Cove and other of those is Lake Havasu. Most state parks have a 2 week limit.
Also recommended: Maricopa County Regional Parks (Metro Phx) here
. Cave Creek, McDowell Mt, Usery Mt, White Tanks. They also have time limits...2 wks I think.
The only Pima County (Tucson) Park with camping is Gilbert Ray
near Old Tucson and the Sonoran Desert Museum on the west side.
Of course, there are commercial parks all over at every level of amenity if that's your cup of tea...check out GoodSam's or Woodall's websites for summaries and links.
The Four Corners Unit (WBCCI) is holding a rally 7-10 April at DeAnza RV Resort south of Tucson off I-19 if you are interested...would be happy to have you join us as a guest. Here's the Forums sign-up page
and all the info you need. You'll just miss our rally in the Sedona area this weekend. Bummer!