Blender is the gold standard when it comes to 3D animation for the average person. It has a bit of a learning curve obviously since it's a full 3D program. If you want to make a full game using only Blender it takes a lot of knowledge. Which is why most creators on here use Daz3D. It's easier overall to get started with for static renders, but I've heard making animations in it is a bit of a nightmare. One alternative is to make the animations in Blender then export them to Daz3D to get the best of both worlds, but as my experience with the program is close to zero I can't help you there.
As an alternative, while I doubt that many people still use Source Filmmaker anymore, even for video game rule 34; as a tool it's super easy to use and get started with, so for simply learning animation techniques in a super simple easy to use editor it's fantastic. It could be worth using that first to try and see if you actually enjoy it before jumping into something with a big learning curve.
I heard some mumblings of making animations in Honey Select as well, but again I have no experience or knowledge with it so someone else would have to tell you more there.
There are mountains of tutorials on YouTube, especially for Blender. So it's best to just start there. They will be able to teach you more stuff that any of us ever could.