After deleting the unwanted parts you can insert the Transitions between the remaining parts to get your video clips smoothly go into one another.
press the Transitions central button;
select one of the transitions displayed within the Selection Area;
drag the selected transition from the Selection Area and drop it between two video clips at the Timeline;
The transition will appear.
Note: it's not possible to add transitions if splitting is done based on
If you need to change the transition duration proceed as follows:
right-click the added transition and select the Transition option from the right-click menu. Enter the necessary value in the Transition Duration field using the arrow buttons or the keyboard. Preview the result and click the OK button to apply the changes you made and close the window.
click the second in the row video clip with the left mouse button, the cursor will turn into a hand. Without releasing the left mouse button drag the second video clip to the left to increase the transition duration.