A 4 week plan isn't going to do much in terms of improving fitness - most plans are at least 12 weeks and more often 16 weeks. If you are looking to get used to the discipline then do some brick sessions (bike then run).
Have you got a smart phone: either Android or iPhone. If so, download Runkeeper and you can set up a training workout, that will tell you (via headphones) when each interval starts. You can set intervals by time or distance.