Tbh, I mostly rely on random Youtube tutorials and started with playing around other creators' models. There isn't really a single tutorial/channel that perfectly teach all knowledges that you need to create 3D model. Most of the time I just look up something that I don't understand / I don't know here and there from any videos. Sometimes, the info that you need is just 30 sec out of a 10 mins video that teaching other random stuff bout 3D model.
I truly don't think I can give the right advice to you as I learnt from reverse engineering bit by bit from many topics. If you are truly want to jump into this, you can pick a format that you want to focus on and start learning every aspects about it. Like if you are interested in MMD, then you focus on PMD/PMX model. For VRchat, may be FBX/OBJ. The list can go on depending on your destination that you want to reach, whether you want to make animation or an avatar for personal use.
The only thing that I can highlight here for you is that, exploring this will need lotsa patience, probably you need to spend 300-500 hours (may be I am not talented) before seeing a significant improvement in model quality. Till today, I think had spent more than 1000 hours over the span of 4 years in exploring different fields of info, like Unity, Blender, Photoshop, Illustrator, MMD, Material, mToon, VRoid, ARkit etc which all of these knowledge can help in creating a model.
Yet, after such time spent. I still feel myself pretty noob in doing this and there is still many to learn.

I just start with donut and low poly model tutorial, I rewatch many times because I tend to get lost in the middle of the tutorial. I dun understand what is mmd or pmd/pmx so I might need to google and see what it is first