Simply click on the camera icon at the top left and see the version screen, like this:
Also, if the CL App manager doesn't show an update, you've got the latest version.
As for your audio issue, typically joining clips together works without any problems, but one way to ensure that there's no gap is to offset one of the clips by some small amount and then use the keyframe tool to manually fade the audio tracks in (for the second clip) and out (for the first), like this:
You can also hold down the Control key and click on the blue Volume level on each clip to create a keyframe directly from the timeline. You'll want to align that with the start/end of the other clip, then you can simply drag the existing ball (keframe marker) at the start/end of the clip to the bottom to set the fade in/out.