"Beáll" sounds more like a vehicle. But you could also use it on foot, for example, if there is some kind of a shelter and you "stand in" there to protect yourself from the rain, wind, cold, etc. But that shelter wouldn't be the "megálló" itself. So it sounds a bit weird with "megálló", unless it is indeed a vehicle.
Well, it is "buszmegálló", "villamosmegálló", etc., ie. the place those vehicles stop ("megáll"). And it often includes a bay for the vehicle to pull out of traffic. But of course the passenger waiting area is also part of it.
I guess what I meant to say was that the little shelter at the (bus) stop is not the whole stop, it is usually just a little part of the larger waiting area. So it is a bit unusual to refer to it as "the" stop. We would rather stand under the roof / in the shelter / in the shade / etc. at the bus stop. But a vehicle that stops at the stop indeed "beáll a megállóba". So, "beáll a megállóba" is typically used for the vehicle.
Does bea'll, in the sense of to pull into to or park, not already give a sense of waiting? I If a car stopped and immediately started again, I wouldn't really call that pulling into somewhere or parking somewhere. Or would this sentence mean that you waited an extra long time or something? Like you expected to be parked here for ten minutes, and it's now 45 minutes later or something?