Understand before we begin…
You can only move Blocks around within a single Page. You cannot move Blocks from one Page to another.
With that understood…
Go to the Page with a Block on it you want to move
Hover over Edit and press Edit This Page.
Click on the Block you want to shift and select Move
The cursor changes to a 4-headed “move” arrow or to a hand (depending upon your web browser & operating system), and long Blocks will shorten in appearance so it’s easier to see your entire Page.
Drag the Block to its new location
To move another block, repeat steps 1-4.