Explore the Dallas Bike Trail system, there are over 100 miles of dedicated, bike trails in Dallas. I can combine the Preston Ridge Trail, UTD Trail, and Renner trail/sidewalk to I-45 and back and do a good 15 miles and I'm only on the street for the length of one house lot. Check out White Rock Creek Trail, White Rock Lake Loop, the Santa Fe Trail. Lots of great places to explore on bikes in Dallas without having to ride on the road, or not much of it.
The bike trails in Garland are all under 1 mile in length I think. Welcome!
Chris