At this stage, don’t think of the running phases as high-intensity intervals. We’re concerned with adapting your body to running, not with building speed. Pick whatever pace you can comfortably hold while still being able to talk in complete sentences. Focus on just maintaining a run or jog. Don’t worry about your pace.
Don’t try to rush things. Your goal should be to keep the effort moderate, while watching your running time and distance magically increase. And of course, your goal should be to avoid getting hurt. A schedule such as the one we’re describing will give your muscles and joints plenty of time to adapt.