Use ripple delete on the empty space and all clips after the space move to the left together.
You can also use the Track Select tool to drag multiple clips simultaneously.
This is in anticipation of the next question. If the applied Transition does not work, as you would assume that it should, read up on "Handles" in the Help files. This is a tripping point for many beginning editors.
If your Transitions do exactly what you want - ignore the above comment, though reading on Handles is always a good thing.