 So, you just need to know how to slide, not a problem. The slide point action defaults to brush radius. If you left click it will grab all the points inside the red circle and move them along the surface of the model. Normally it will try to keep the point on the edge it's sliding, but if you hold shift you'll be able to stop snapping to the edges that you drag. If you hold alt while clicking it will move the points forwards and backwards. Under modifiers you can change the settings, infinite x drags all the points horizontal to the one that you click, and infinite y does the same thing but vertically. The depth just means it will grab all the points even through the object on the backside. Infinite x y z does the same thing but with the full brush size, and infinite z is similar but only for the z axis. Hope that helps and as always I hope you have a fantastic day and I'll see you around.