Petropavlovsk-Kamchatsky — unless you are touring with a company based in Yelizovo, the next natural destination is Kamchatka's capital and largest city by far, which is a bit more of an interesting place to hang out, and which has a great deal more in terms of tourist infrastructure, including most of the tour companies catering to foreign tourists.
The Yelizovo bus station 53°11'6"N 158°23'19"E serves routes to Termalny via Paratunka once an hour, Esso early in the morning.