Custom humanoid tips?

I want to create a custom humanoid system since most of the features in the default humanoid are useless to me.

What are the best methods of replicating the exact behavior of humanoids? There’s a very specific way that the humanoids stay elevated and move around. How can this be copied to be basically identical from the perspective of a player?

I only need need these custom humanoids to do three things: Stand, Walk, and Jump.

I don’t really understand but i think it’s about humanoidstates