You need to set up your material properly. It’s unlikely something on Turbosquid is going to import to UE4 correctly unless they design it to. That’s the reason for the Unreal Engine marketplace since those assets are designed for UE4.
You have a specular map and a normal map for your two materials, you need to plug them in and check that they look OK. I can already tell though that you don’t have the normal map compression applied to those normal maps which means they won’t render correctly, you need to adjust the properties of those through the content browser.
After importing a few items, here’s where I’m currently at.
Which is much better than previously. However, I need help getting it to look like the picture above. If anyone can help with that, I would be most appreciative and would be more than willing to pay. Please PM me if you believe you can help. Thank you.