The RYA offer a wide range of dinghy courses. These can be an excellent way to start sailing, especially for youngsters, and will provide a range of skills such as wind sense and sail trimming that are transferable to yachts. Indeed, dinghy sailors are often better at setting sails on yachts than those who have gone straight in to yachting. I guess there’s more incentive to getting it right on a dinghy, where unlike a yacht, poor sailing handling can result in a capsize.
However, an RYA dinghy certificate is not generally accepted as a qualification for chartering a yacht. And for those wishing to take a yachting course, there is no requirement to start out on dinghies.
The main source of dinghy courses overseas are at Beach Clubs. Some Beach Clubs also have yachts available for day sailing, though these are often older yachts retired from flotilla. So if your party includes those who want to dinghy sail and those that appreciate something bigger, a good combination is a week at a Club followed by a week on a Bareboat or Flotilla yacht.