To make the setup in material easier, you can use the add-on "Node Wrangler" that came with Blender. If you want to use the AO map you  can add it using mix node and switch it to "multiply" then put the base color on top and AO on bottom slot.

Make sure at material tap, under setting change displacement to "displacement and Bump" if you want to use height map. 

.1 - .2 displacement scale works best.