To cut an entire clip, you only need to click on it and then hit "delete."
To cut just a portion of a clip, you can select the area using the green and red tabs on the sides of the playhead before clicking on the scissors icon at the top left of the timeline. Note that if you cut in an area with several layers (such as below), all of those layers will be cut as well.
On the bottom track (which is the video and audio recording), the tracks appear to be sewn together were the cut was made. This can be helpful for reviewing the cut afterwards.
To edit a transition, just click on it. You'll be able to change the type of transition in the "Properties" menu to the right of the canvas. To change the speed and duration of the transition, you can click on the edge of a transition and drag it.
Sometimes, the edge of the transition is tricky to click on. If that's the case, use the slider near the scissors icon to zoom in (as seen in the second GIF)
Grouping can be grouped together by selecting more than one and then right-clicking to open a menu (as seen in the first GIF below). Grouping tracks can be handy in a number of ways.
Degrouping can be done by right-clicking any group of items. To edit grouped items, you can just double-click on the group and it will open the group in a new tab (as seen in the second GIF below)
