Crewing Opportunities – where to find positions on boats (and where boats can find positions for you) Some require a membership and fee.
There are lots of others available online too.
International Yacht Training Worldwide
Sailing Schools (I can only recommened ones that i’ve used and been happy with)
Allabroad Sailing Based in Gibraltar
Endeavour Sailing Based in the Canary Islands
Faro Sailing School Based in the Algarve, Portugal