GMS 2 build in game


come costruire in un gioco? per esempio il giocatore costruisce una navetta spaziale montando i pezzi nei giochi


how to build in a game? for example the player builds a space shuttle by assembling the part in the games


That's a very broad category, it completely depends on the game you want to make, but it usually involves creating instances with instance_create_layer() or instance_create_depth() (instance_create() with 1.4)
That could be done in so many different ways and I don't think anyone will want to design this for you. What you can do is, start from making a platformer and get to know the GML so you can think about how you can achieve your goal.

But to basicly tell you,
You can check variables like
if (RearPartIsCrafted == true)
{ draw_sprite(fillthis); }
And draw parts if they are crafted. Though that wouldn't give you collisions.
So you may need to Create objects instead or something else about it.
This is one of those questions that unfortunately ends up being answered by "If you don't know how to do it already, you're probably not ready to do it." It can be quite a complex undertaking and isn't necessarily fodder for a beginner programmer. It basically breaks down into three separate things:

1. Let the player select what type of thing they wants to place. This could be done via buttons, dropdown lists, etc. None of this functionality is built-in and you will have to assemble it from scratch. Once they've selected the piece they want then...
2. Let the player create instances of the thing they want to build when they click (or whatever the input method is). This is as simple as using instance_create_layer, but it is usually a lot more complicated as...
3. You have to be able to build a data structure that relates to what they are doing. If they are connecting parts, you need to be able to use a map, or a list, or a buffer, etc, just a data type to "graph" the relationships between the pieces. Not only should this data structure keep a reference of each relationship between the pieces, but it should also be storing required information about the part itself so that when the player gets around to using whatever it is they've built, you're able to reliably rebuild the individual pieces and their relationships to each other from only the data you have stored.

If what I've just said seems like gobbledegook, then, as I said at the start, it might be beyond your current level of programming ability. If that's the case, I'd recommend starting with a simpler project, while researching and experimenting with Data Structures and storing information about instances so that you can come back to this project later with a better foundation to build from.