Assuming you’ve got the basics of playing prebaked animations down in Unity, one of the next things you’re almost certainly going to need is Inverse Kinematics. If you’re not familiar with the concept, what IK basically does is enable bones to move to points in space automatically, rather than having to explicitly define the movement of each bone.
To get started, install the Animation Rigging package in the Unity Package Manager. Once this is finished, you’ll want to define an IK target. This can be as simple as an empty game object, but will of course vary depending on your use case. Next, you’ll need to add a Rig component to a child object of whatever you’re trying to animate.
Within your Rig, you will want to create child GameObjects for each of your IK constraints. The default constraints provided by Unity each work quite differently from one another, so you will have to pick whichever one best fits your need, or create a custom IK constraint if you’re doing something unusual. You can find the list of constraints here, along with further details that make it pretty easy to get IK up and running: https://docs.unity3d.com/Packagesemail@example.com/manual/index.html