In Wave.video, you can trim your video clip. This feature works both for your own video clips that you upload to the video maker and the ones you choose from the built-in stock video library.
In order to trim the video clip, click to highlight the video and click the button "Trim".
You can then trim the video clip. You can preview the piece you've selected to check if you like it or not. In case you need to restore the original video length, simply click the Trim button again and select the necessary piece.