How to use gloss And reflection map in material function

I’ve downloaded some texture packages from poliigon.com, which is not a site of textures dedicated for UE4, so i don t know if the reflection and gloss map can be used in the editor. Also, i have a Disp map from the site, which i think is Displacement and i’ve set it to vectorDisplacementMap, i don t know if that was required. I plugged it to world displacement.