Can I double buffer images in basic, or can I use the assembly while still in basic, or something that would allow me to double buffer it but keep everything else in basic?

You can't really use double buffering in Basic, but an assembly program can be used while keeping everything else Basic, kinda like how Michael2_3B did with his Shades 84+ CE Port. There are also things like Celtic CE, which give Basic programmers access to powerful assembly functions, though I am not completely sure if or how double buffering can be done using it.

So how would on use the assembly to double buffer?

I believe double buffering in basic isn't possible. If I understand it correctly, it's because ASM programs use 8bpp mode which is half of the 16bpp mode that TI-OS (and thus, TI-Basic) use. 8bpp mode means ASM programs have extra memory to store a second buffer. However you cannot run TI-Basic programs in 8bpp mode or the UI will get all corrupted. Therefore you're stuck with just a single buffer.

What do you need a second buffer for? BASIC is typically too slow for it to be any concern.

I want to have a hanger where when you change your ship then it loads the ship and it looks ugly of it loads the ship from scratch. So I want to have a “loading screen”

xLIBCE can provide double-buffering, used to good effect in my STEM Behind Hollywood ports to the TI-84 Plus C Silver Edition. Unfortunately, you're probably talking about the TI-84 Plus CE, which doesn't yet have xLIBCE.

So is there anyway I could load the image without having the image up here while loading it like while
Drawing it out?

You would need to use C I think. There are two libraries for TI-BASIC programmers that can chain commands together in a way that drawing graphics is less flickery (CE Textlib and grosged's Sprite v3.3 library) but it's still not double-buffering.

Just like have a loading screen for an image that’s gonna get stored. Like an simple fix

On the ti 84+ NOT CE, you can draw to pic vars, then overlay them, which allows for some cool effects, but if you mean drawing to something that isn't the screen, yeah no.
Unless you're talking text graphics, but at that point, it's pretty trivial.

How would you do the overlay