Re: Looking for Spelljammer
In theory, you are supposed to be able to use a D&D 5e character with any other version of the game. At least, that was the original premise behind 5e. The editors wanted a version where all other variations of the game could be used together. I don't really know whether they succeeded or not, and certainly the game has moved on since then.
Try searching through existing games that are still accepting players.