Enter edit, create a new vertex group on properties/object data/vertex groups, enter 0.5 in the slider at the bottom of the list of VGs, select all verts, hit the assign button at the bottom of list of VGs.
The less pinning/goal you use-- generally speaking, the lower the weights in the pinning/goal VG-- the more freely the physics object will react to physics. But of course, the more it reacts to physics, the less control you have over it via direct animation.
IIRC pinning, for cloth, can only be modulated by vertex group assignment (although you can use vertex group modifiers to modulate it dynamically), while soft body physics has a few more controls in the physics section.
One thing that I sometimes do, that you might find useful, is to use non-manifold meshes for my cloth/soft body physics, with extra loose edges leading out to fully pinned verts-- “sewing” lines for cloth, but for soft body, it’s the same principle. Then, using an armature or other deforming modifier on only these pinned anchor verts, I can exert control more indirectly than via direct transformation. This will screw up your normals, so you’d need to restore them with a modifier, (or custom normals or normal mapping, maybe) or make the physics mesh non-rendering and use it only as a surface or mesh deform for a different, rendering mesh.
Quick demo file: physdemo.blend (602.4 KB)