Here is the local figure skating club for Twin Ponds East:
https://www.centralpennfsc.org Perhaps you could figure out someone in the club to contact for info? They've links for contacts, Facebook and Instagram. You don't trust the rink itself to tell you how many people come?
FWIIW, there are other somewhat local rinks (Twin Ponds West, Klick Lewis Arena, Giant Center, Hershey Park Arena, though the latter two are mostly special events and some public skating).
But I haven't skated at any of these rinks, and cannot review them.
P.S. have you ever tried roller skiing? Some Youtube videos look insane, especially on hills. (Then again, a lot of ski videos look insane.) I wonder if it is closer to skiing than inline skates.
BTW, I once bruised myself on a Roller Blade fall, though that was partly because I was nervous about sliding on asphalt, and reacted wrong. There is nothing wrong with using helmets, padding and protection. I suspect padding won't be a problem at your lesson - Roller Blades sells some of it. Wheels can move much faster than ice runners, especially on hills; concrete and asphalt develop more friction on body slides than ice and snow; turns and stops are harder (you kind of have to jump into them); curbs can make you stop rather fast if you don't jump them; you may have to share the road with motor vehicles. The guy who sold me my roller blades (Don Giese) offered a free skating lesson, which included how to avoid being hurt if a car runs into you, or vice versa - he was a racer, and racers can be ever so slightly crazy.
I think roller blades are used for training more by XC skiers than alpine skiers, but may be wrong.
There are a lot of skate parks you might play in. Lots of them are right next to ice rinks, and might provide a good warmup while waiting for an ice session. If not, there is always the parking lot.
P.P.S. The Mananda Hill exit off route 81 is probably the cheapest place to get gas a bit north of Harrisburg, if you are coming from that direction.