Will i need texture?

I made somewhat of a cannon. Im beginner at blender so the modeling isn’t great.

But my question is, would my cannon need any texture to it? I dont really see cannons with texturing, mainly just 1 color for the entire mesh.

Also, how should i do the subsurfing? Some parts of the mesh need it and some dont.

If you are just starting out, you don’t NEED a texture. But look up images online, and you’ll see nothing is truly one color. You need to add some noise, some cratches, some bumps, and some reflection to the material to make the metal look real.

about subsurf, You can manually select the part you want to subsurf in edit mode, hit the W key, and select sub-div smooth.