In game ship builder/editor

How would I create a in game ship builder that allows players to create custom ships from available parts? How would I allow player to save it?

save/load: Storage - GDevelop documentation

as for the implementation, first you need a design, because there are countless ways of doing it.

I really just need help with snapping parts together and saving and loading

snapping: Stick objects to others - GDevelop documentation

I already gave you the way to save/load.

That’s all?

You can use custom points on objects to which other part objects are attached, and then use the Sticker extension to keep them in place. For example if you add the Sticker behaviour to the helm object, and set up the ship body with points:

image

then you could position and stick the helm object like:

The object points work thanks.