The main window of MyFiles is called explorer and is divided into three views or panes: tree (left) pane, list (bottom) pane, and a property (top) pane.
There is a nice title bar at the top of the explorer window. It shows you the path to the currently selected item. There is a status bar at the bottom. It shows you a total number of items in the tree, a number of items in the current branch, a number of selected items in the current branch. It also shows you a number of items in green and yellow filters respectively in case you've switched to an active filtered mode.
Right-clicking the mouse in the list pane or property pane produces a context sensitive menu. All of the options listed here are accessible through the main menu and are explained in the relevant parts of this documentation.
In explorer you may also use "drag & drop" to move items or item groups from one branch into another. It can be done by selecting the required items in the list pane and moving them over to the desired item in the tree pane with the mouse.
You can change current sorting in the list pane by clicking over the property column header. Subsequent clicks will cause the sort order to reverse.
You may change the dimension of panes relative to each other by dragging their floating dividers with the mouse pointer.
Increase your productivity by using keyboard shortcuts. Explained in the corresponding topic.