Okay, I'm going to be first to comment here
I think you get the basic concepts, but I think the model may be a tad bit too low poly.
I've seen too many people come here and really obsess over low poly this low poly that. Especially people that are just starting out with modelling. And it hampers the way they want the model to look.
I think you should focus on making the model exactly (or very close) to how you see it in your mind, and focus on poly count secondly.
It doesnt mean going overboard on the poly count in the 10's of thousands, but just keep it in the back of your mind, so you dont go overboard.
That way you can work on making the model appear how you exactly want it to.
Also, for character's that are going to be animated, you will want to add more loops around joints (or other places that bend) so the mesh deforms well.
But overall not a bad start.
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