The FBO on the field is Energy Aviation, +1 (570) 368-2651. The FBO is on the West Ramp. Operating hours are 0630-2100 LCL. After-hours fuel by prior arrangement.
Canyon Aero LLC rents aircraft and has flight instructors on staff.
There are several other CFIs in Williamsport, at least half a dozen, probably a dozen or more. I'll add them to a list here as soon as they give me their preferred contact info.
You can learn to fly Light Sport aircraft at AvSport of Lock Haven. LSA rentals and maintenance available.