I recently started learning Houdini. Before that I studied Blender and Maya. In Maya, to animate a vertex in edit mode, just place the keys. As soon as I did not try to find the answer for key queries, but everything is not right. So, I just want to take one of the cube's vertices and move it a certain distance. And animate this action. Can you suggest how to do this in the most simple way. This is the base from which I will continue to build on.

Houdini doesn't animate vertices directly. Only parameters can have animation channels. The transform node has parameters that can be animated and the group field can restrict the transform to a single point (vertices in Houdini refer to topological vertices and don't have a position).

The animation could also be done with a null object, with the desired point constrained to the null.

Yeah worth having a read of these if coming from other 3D software:
https://www.sidefx.com/docs/houdini/model/attributes.html [www.sidefx.com]
https://www.tokeru.com/cgwiki/index.php?title=Points_and_Verts_and_Prims [www.tokeru.com]