Marketing plan templates are developed by people who have achieved success online. They capture the lessons the author has learned along the way and save you the time, cost and effort required to develop your own. Once you have mastered a particular marketing plan approach, you can then expand by refining the template you have used or by adopting another template that might be more suitable for the marketing of a different product or service.
However, if you do not want to spend money or you cannot find one that would suit your training ideas, then try the integrated approach. You can look up other companies' templates online and then make a few revisions to make it fit your own approach. If you are lucky, you might even stumble upon a training plan template from a company that is within the industry your business belongs to.