Logic (which GarageBand is based on) has a GoTo shortcut, where you can enter a bar and then just locate to that bar anytime with a quick two-click (the GoTo shortcut and Enter), but this doesn't seem to be implemented in GB (I tried it, but no luck). Of course in GB Play will start at the beginning of a Cycle (when enabled), or a selected Region (with Shift-Spacebar), but the playback cursor doesn't move to that bar until you hit Play. AFAICT the closest you can get in GB is to quickly double-click the Bar display in the Header and type in the desired Bar number, or click the desired bar in the ruler, or shift-click the desired bar anywhere in the Track area background. Not really what you're looking for, I knowâ€”I use the GoTo shortcut in Logic all the time. Logic also lets you set shortcuts to cue up to Marker locations, so I tried making Arrangement markers in GB to see if I could get that to work, but again no luck.
So it looks like the answer in no, but I'll link this thread to a GarageBand course, maybe someone who uses GB more often will have a suggestion..