Thanks for sharing. Expand the sequence by moving the slider at the bottom-right of the window to its far-right position. Right-click in the blank area just ahead of the first slide.
The sequence will be at the start and you should see this...

Click CLOSE GAP IN TRACK which will eliminate the space that's ahead of that slide.
Also, because audio volume is low, suggest selecting (highlighting) all audio clips. (Select the first, hold down <shift> and select the last.)
Now click the FX button on any one of those clips. When the effects box appears, click the large green + sign in the toolbar.
Choose the NORMALIZE effect. Finally, click the fourth icon from the left on the toolbar. The pop up will read "replace effect chain in other selected clips."