How do I start a workout from training plan without having to choose a course?

Hi. I have set up a training plan in Garmin connect (just one of garmins ready made plans). When I want to go out and do the workout I can’t get the workout to start. I go through the options menu>training>training plan>select the workout scheduled for the day, from there I would have expected a start workout option but that’s not possible as the only options are find a course, weather and find a workout. I don’t want to have to set up and use a course but just go for a ride and do the workout at the same time. Even when I do choose a course and select ride it doesn’t display the workout data and appears that you are simply doing a ride. Please help. I assume I’m doing something really basic wrong. Thanks.