In addtion to ham, there is the GMRS, "General Mobile Radio Service." This is sort of a licensed UHF CB band. No operator's license is required, but in the US a station license (call sign) is currently needed. You can get this by filing paperwork and paying about $90 for five years. The callsign is good for yourself plus extended family members. They would be WXYZ123 unit 2, unit 3, etc. or whatever unit identifier you choose among yourselves.
In the US, there are 8 channel pairs for radios up to 50 watts (six pairs near the Canadian border), operating direct mobile-to-mobile or through a repeater. If you have the skills, you can put up a repeater, or you can join a group that operates one. Many REACT and search-and-rescue groups have established GMRS repeaters.
The GMRS band is at 462 MHz, in the middle of the UHF Public Safety and business bands, so UHF radios (except "T" band) need no modification.
The license-exempt FRS handhelds sold in "blister packs" in big box retail outlets are on GMRS splinter frequencies between the high power pairs. A GMRS license allows you to use 5 watts on the FRS channels (except see the Canadian border rules). This is good, because you can buy a half-dozen cheap handhelds to use around the campground to communicate with the UHF radio in the bus on an external antenna. It's no heart attack if Junior lets his Wally World or Home Depot hand held slip into the lake while sitting at the fishin' rock.
In Canada, I believe no license is needed, but there is a 2-watt limit and repeater use is forbidden. A high-power UHF radio left over from a school district would not be of benefit there.
Someone said "Making good decisions comes from experience, experience comes from bad decisions." I say there are three kinds of people: those who learn from their mistakes, those who learn from the mistakes of others, and those who never learn.