If you’re new to Tucson, the 4th Avenue shopping district goes along 4th Avenue from the northern end at University Blvd. down south to E. 9th Street, and the 4th Avenue Underpass.
And since July 25, 2014 you can get there via the new modern streetcar Sun Link from either the University of Arizona, or from downtown and the Mercado San Agustin out west of the I-10.
Lots more info about shopping & eating along 4th Avenue at: www.fourthavenue.org.
Enjoy shopping locally.