@singnsmile
Welcome to Mayo Connect.

I am assuming you meant 4/10 appointment instead of 3/10 at the Rochester downtown campus. At that time, you do not check in very early. Most areas will not allow 30 minutes prior to appt. If your hotel does not provide a shuttle that early, I suggest parking at the Graham parking ramp. At that hour, there will be plenty of spots. Valet parking starts at 6 AM, so that is another option.

This website might help:
https://www.mayoclinic.org/rochester-construction/downtown-patient-arrival-departure-routing
If you want to share the location of your appointment, I can try to give more details