I want to try creating hair for Sims 4, where should I start

Hi. I assume you’re talking about maxis match hair?
1. Learn how to recolor, this is pretty easy. If you don’t have photoshop, you can use photopea (free online alternative, almost identical to photoshop, so you can follow those tutorials with no problems)
2. Watch a video on hair mesh editing ( changing the length, removing unwanted parts, re-transferring data, making lods, re-baking a shadow map);
3. Watch a video on frankenmeshing (combining two meshes together, re-arranging uvs, re-baking textures);
4. Optionally, you can learn how to add strands to existing hair

After this, you will be able to create any hairstyle from existing onesWhat do you mean buy "Maxis Match hair?

I was forced to get Photoshop a few months ago because I also make mods for Resident Evil 2 Remake, and you need Photoshop for that, but thanks for the 411 on Photopea!  I also have Paint.net and Gimp, but most of my experience is with Paint.net

As for Blender, I do have some experience with that program as well as *SOME* exposure to 3DX Max

What I really need now is the URL of a specific BEGINNING HAIR tutorial.

Thanks again!