Woah, that's an unexpected decision! TOTALLY do it. I'd love to wrap my eyeballs round your OCs in all three dimensions.

At this point, you could go for either. From what I remember, plenty of the add-ons that improve workflow and QoL stuff like TexTools are compatible with 4.0 and plenty of the 3.x tutorials are mostly compatible or can be sussed out with a little guesswork/experimentation.

The things relevant to what you're wanting to get out of it are that 4.0 changes how bone grouping works in rigs, there are some slight changes to how shaders are laid out, the UI is altered to be a bit more streamlined, and there's a new rendering engine that wasn't present in 3.x.

Well I am also going off of someone I know who also uses Blender, he says that 3.6 is what he uses and he's made some animations with 3D models, so I trust his input.

So here's the thing about Blender: Yes it's free, and quite powerful out of the box, but the longer you use it the more the ecosystem of plugins calls to you. And the more plugins you use, the harder it becomes to do major version updates. 4.0 required rewrites for many plugins, so those of us who have workflows that rely on them stayed on 3.6 for a long time, or may still be on it.

As a new user who hasn't bought into any plugins, going with 4 makes sense. It has improvements worth having access to, and you're not going to feel like you're missing anything.

And as a final note, Blender makes it very easy to have multiple versions installed. If you go to the download page and click the button that says 'Mac, Linux, and Other Versions,' you can download portable versions of the program and swap between them if there's some legacy function you REALLY need.

I used to do blender, 3.something. back in high school where I did it at a vocational school for 5th year thing. They also taught me web design.
They changed the UI on the next update which made everything harder for me, with muscle memory and stuff. I've heard it was to better make movies from a discord user making a meme about it.

Though I believe the shortcuts are mostly unchanged.
Blender's kinda meme'd as that software that you can turn the default cube into landscapes of donuts and the most optimal way to do that is to use a dozen shortcuts with the only breaks from that being to type in some values or moving your mouse a bit, and that's not that far from the truth. So the 3.0 stuff should work for 4.0 for the most part.

Just make sure you have a full keyboard, one with a numberpad. Speaking from experience.

4.0 has a lot of new features like bone collections

"Having conquered the realm of 2D with their body and frame growing to scales unheard of the masses, Jeri turns to the 3D space to fill the third dimension with their ever growing body."

Anyway, I just wanted to say that, whatever ya choose I hope it gives you a good time filling the new space-time of it all.