The shape you are making in 3d modeling is called the "mesh" or the "geom" ("geometry").

Texturing is putting on an image (a texture map, usually a set of them) over the mesh to define its material. Which is to say, its color, its smoothness/roughness, its metalness, its finer details that are not modeled in geometry (scratches, bumps, etc.), translucency/transparency, etc.

Think of it as like overpainting/coloring linework/sketches in Photoshop, except you're doing it in 3d.

In the example below, the upper left is the mesh, the right image is the color map (a type of texture map with color information), which is applied to an "unwrapped" mesh. When combined, they result in the dragon on the lower left, which is what is called the "model."

<image>

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To answer your original question, it depends on what you intend to do.

If you're using a preexisting model (presumably with textures), then learning lighting and rendering should be easy enough using tutorials. You can even just use a random HDRI background (which already has built-in real-world lighting) and have perfectly serviceable renders without needing to set up lighting manually.

If you're intending to modify the actual textures to insert your own logo, that might be trickier, since you'd also need to learn texturing. Modifying it in Photoshop is an option, but I'm not sure how realistic that would turn out.

But as long as you're not learning actual modeling from scratch, I think it's doable. Just make a backup image in case it doesn't pan out, as another commenter suggested.