In your object's shape attributes, look under the tab and turn on Subdivision . Set the type to Catclark and iterations to 3 or 4 to ensure the render engine tessellates the geometry enough to read the fine micro-pores. Mastering Specular Roughness and Micro-Gloss
Set your to around 0.3 to 0.5 for realistic facial skin.
With the model prepared, artists utilize projection texturing tools.