[help plz] WarioWare Get It Together - Ripping In-Game 3D Models (and other stuff?)

[Boxy]

I took a look at your 9-volt dae, here are the results: https://imgur.com/a/IXZkPCq

The basic things you need to do in blender are: link the textures, and rotate a couple of body parts -90 degrees in the Y axis. If you look at my images, look at what I have highlighted on the right-hand side as a guide as to where to do these edits.

If you need help with any others let me know. I can also send you my blender file.

Yeah, i would use your dae as a reference, because really idk how to use Blender for all that stuff. (I did rotate some parts to -90 degrees right now.) 

I'm looking right now at the color/texture stuff, i tried changing the base color of the helmet and there's no effect or how do you use an image as a texture?
https://imgur.com/a/8FL840V

It looks like you're in default shading mode. In the top right corner of the viewport, click the ball icon one to the right of what's currently highlighted. That should enable textured view. (You can try clicking the other ones too, one is wireframe view, one is render view, etc.)

With textured view on, now any textures you have applied will show up. Also pretty much any time you need to apply a texture, just make sure 'use nodes' is on, then right below that click on the dot next to Surface and select Principled BSDF. Then right under that, click on the Base Color dot and there should be an option to select 'Image', which then lets you click on a folder icon to load any image you want.

That should get you started hopefully. There's a whole other workflow for UV editing, and shader node editing, which you need to edit to apply the eye, mouth, and visor textures correctly (those require alpha transparency). I'll send over what I did (by no means perfect/complete) tonight.