I think the engine folder in the asset browser has a few material functions that you can call in your material and those are made specifically for these things. You might want to search for those and bring them in your material then plugging them in. My answer to your issue is that you have to learn a bit the workflow of PBR and start evolving, Plugging 1 or 2 nodes wont do the job always. You will have to do a lot of things in order to get it right, But once you got it right you will have a basic template ready for this kind of objects. Metallic, Organic and so on.
PS: You can also open any of the example assets materials and see how they have those set up, They use those functions i mentioned about too.