jrlowe24 so first off, this is PBR, you are not supposed to "play around" with the settings.
second, the sketch fab has a model inspector where it shows you more options, and you can toggle to see the different textures and effects applied.
by default it has post-processing applied. this depends on two things: the environment and the effects.
for the environment, you NEED a skybox, the default environment sky is going to look dull.
so go to ambientCG or Polyhaven and download a HDR sky (it's CC0). with godot it's enough with an .hdr, a .exr has more quality but doesn't work well due to formats and it's heavier.
alternatively, if you are in an interior level, you also need a VoxelGI or baked lighting, or reflection probes everywhere. alternatively you have FDHGI or whatever is called, which a pseudo-pathtracing, but it's very heavy, it's better for exteriors.
alternatively, or on top of this, you have to enable SSR, SSAO and maybe SSIL.
SSR gives you screen space reflections, it's good for self reflections and puddles of water.
SSAO gives you cavity shadows, you can see it in sketchfab. it is very lightweight for modern computers since it's been around since skyrim.
SSIL can be added on top of other post-processes/GI and it adds lighting by pathtracing a reflection. don't worry, it's very lightweight.
you also want to change the color to either linear or ACES. ACES is heavier but gives better results, but unreal and unity use linear by default.
you need one of these for PBR, PBR will look bad with anything else.
then set up your material.
it is recommended to get or create an ARM texture (ambient occlusion, roughness, metallic): the red channel has an ambient texture (which I guess did not come with this model, but your could bake one in blender), the green channel is for the roughness texture, and the blue channel is for the metalness texture.
then create an ORM material and assign your ARM.
this model also comes with a specular map, for this you have to take your material with all things assigned, convert to shader, add a uniform for a specular texture, and then in fragment, connect it to the SPECULAR.
having a SPECULAR is not very PBR though, I don't know if it will work.
DON'T mess with the textures import settings.
your model textures should ALL be set to VRAM compressed. in order to fix the artifacts you have to enable high quality in the same import tab.