How to use a Garmin watch for an interval run?

How to use a Garmin watch for an interval run? I am a beginner in running and would like to do some interval runs. Right now I do not know yet what "rest" interval will be good for me. I have a Vivoactive 6 watch and would like to use is in a mode "now I am running, and now I am walking" so that it classifies both activities separately. Is this something I can set up? Right now I just stop the watch when walking but it is still part of the routine, classified as running. Note: I checked in the Help Center if questions about devices can be asked and it looks like they can. Feel free to delete the question if it is not appropriate here, thanks!