How did you create your geometry? I have a feeling that your issue is mesh related.
I used a lofted sweep with guide curves to get the initial shape. Then I used an extruded cut to shape the cockpit. Finally I applied a 4mm shell in order to hollow out the body.
Attach your *.sldprt file here.
your errors are saying that your parts aren't connected correctly
start much simpler
start with the structure underneath, gravity load, fixed restraints, get taht to work
then add a couple other parts...etc
once you get the hang of mixed meshing you can eventually put this together
you're going to need some patience here and i woudl recommend building some simpler models to get the hang of it before you go for the gusto with your full model
you need to learn beams, shells, mixed meshing and contacts. there are tutorials for this that i'd start with.