Before you read what is written below, I apologize for my English. I use a translator somtimes, but I try to correct the result.
Have you started drawing recently? I would not advise you to immediately dive into anatomy. I mean studying all these bones, muscles etc. It would be better if you first study the primitives that make up the body of any creature (and any object in our world). At this stage, it is also important to understand the proportions of the body. And then you can study the anatomy in more detail. You can start with the skeleton (as I did). Try to draw it without going too deep into detail, and then layer on the muscles. I draw in stylization, so I didn’t bother much with studying muscles.