Findacrew.net - Typically private boat owners looking for a hand on crossings. No experience might make this a bit of a push and I havent used it for about 10 years so…
A better chance might be to try and get ahold of the merchant navy.
Plenty of big ships that take a volunteer crew, especially for ship delivery. They can be picky about who they make shipmates, so dont sound fucking useless if you contact someone. Competition to be crew can get fierce.
Depending where you are, most seem to do the business on Facebook.