Looking good from my perspective, however I think you should concentrate on getting the basic forms down first. You are jumping too fair ahead with the detailing. I appreciate that you are new to this, continue to study anatomy and you will improve.
totally agree with tidyfiguremaker
for just starting out this is good!
I refused to look at references in the beginning because it felt like cheating but now I can't stress it enough when it comes to learning anatomy!
just a few big things:
the waist is way too narrow
the abs are not apart
the deltoid reaches further down the upper arm (around 1/3 from the acromion process to the elbow) and it doesn't reach into the neck area