i strongly disagree. Focusing too early on the fine details rather than the broader shape is a mistake I see lots of beginners make. Sure, there is a place for sculpting these details, but in my opinion, as a beginner, you should not care too much about the details and focus more on getting the big/medium shapes right.
For doing game-ready stuff, I think it’s almost always a better approach to do the fabric and surface scratches using a height map or other texture paintingapproaches.
In the end, I want to clarify that this comment may sound more evil than it should have. I totally get that sculpting these details is fun, and in the end, having fun is kind of the whole point of creating art in the first place.
there is a guy how does a lot of robot modeling, there he uses a two subdiv workflow that is really good for doing simple and fast hard surface stuff. I think i would do it like that, here a link where the workflow is explained: https://youtu.be/FB8rBDLw3iE
its probably good, that when you have no reference for the head to take a base mesh from https://www.blender.org/download/demo-files/
I used the human base mesh bundle a lot as a reference when i did masks