Drop into Photomark -- has quite a selection of Large Format and lighting gear (Rod Klukas). Just north of the airport.
Also Tempe Camera is just west of downtown Tempe.
Just a mile north or so of Tempe...
Phoenix zoo is always interesting. Go early in the morning.
Desert Botanical Garden next to zoo should have early desert blooms started.
http://www.tempecvb.com/
Rent a car --
Go do the "Apache Trail" up in the Superstition mountains (starts in Apache Junction and ends at Lake Roosevelt, north of Globe)
Nearby is "South Mountain". Small chance of wildflowers, but the nighttime views are great from the summit in early evening with Phoenix stretching 100 miles west to southeast...
Lots of other things to do outside of Tempe, but two days is too short...
Tucson- Arizona-Sonora Desert Museum (Not really a museum but a zoo of all the desert creatures...my first experience was back in the 70's..paid at the entrance and walked into the reptile house to see the museum dioramas of the lizards and snakes...was it a surprise when the first lizard opened their eyes and moved....dioramas were like those at Museum of Natural History in NYC, so live animals weren't expected).
Tucson - Saguaro National Monument.
Tucson - San Xavier Del Bac Mission (Kino era..."White Dove of the Desert")
South of Tucson - Missle Silo (you can tour...)
Tucson, north - Mt Lemmon (one of 3 Ski areas in Arizona)
heading North of Phoenix: Sedona, West Fork, Grand Canyon, Route 66.
heading NE of Phoenix: Mogollon Rim (Payson east to Snowflake), Petrified Forest, Canyon de Chelley, etc etc
Basically - two days - you're limited to the few lines at top.....
have fun. Lodging this time of year will be incredibly scarce (and expensive) with all the snowbirds in town.....