This is perhaps the quintessential "Carry On" film, which also means that it's terribly dated when viewed today! That said, it's quite funny scene by scene even if the plot itself is alarmingly thin and disjointed.
In fact, it follows three separate narrative threads during the first half which then come together: one involving Sid James and Bernard Bresslaw and their girlfriends, sisters Joan Sims and Dilys Laye; another with bickering couple Terry Scott and Betty Marsden, who pick up annoying drifter Charles Hawtrey along the way; and the members of a finishing school (including perky Barbara Windsor) and led by the series' all-too-typically reserved authority figures namely Kenneth Williams and Hattie Jacques. With this film, the bawdiness which has since become synonymous with the series really took off beginning with the very opening sequence, which finds James et al in a cinema showing a documentary about a nudist campsite!; a scene in which James and Bresslaw spy on the women's baths through a hole in the wall was subsequently much imitated.
Many of the film's best moments highlight Terry Scott exaggerating his afternoon activity when asked by the wife how it was, knowing full well she isn't lending him the slightest attention; his encounter with a bull in a field; at the end, when he takes stock of the situation in his tent and forcibly throws out Hawtrey. Popular British starlet Valerie Leon, who appeared in a number of "Carry Ons", has a bit here as a salesgirl. By the way, CARRY ON CAMPING was trimmed by the BBFC on its original release; ironically, it ended up being the highest grossing film of the year in the U.K.!