So i did mi plane but i made a mistake because when creating the wings, i didn’t extrude from the plane I just add a cube and start creating them. I want to merge this 2 abjectos so they become the same.
Just want to put together the parts. Like if I extruded from the plane and from there create the wings.
Thank you if you help, and i now it looks… horrible but just starting 
When I did it, I ended up extruding the wings to intersect with the body of the plane. Then in object mode, I selected both wings and the body, and hit ‘join’. That made all of the parts into one object.
Of course, there are still bits from the wing poking inside of the plane body, but you can only see those in wireframe.
It tells me “no mesh data to join”
I see they are already 1 object, if you want to remove the “inside part” then its a bit more complicated if you’re fine with how it is now, just put the wings where you want them and press TAB to exit edit mode, done. If you want to actually connect them (this is mostly for texturing etc) then i took a few screenshots trying to show you how.
Thank you m8, it worked 
glad to help
