Who downvoted? It's an honest question. I saw myself in your position a few months ago. I think you should read the Rails Guides and play some Rails4Zombies first because you are confusing two parts of Rails, the model and the controller.
Controller actions are like things that you can do with your app. In this case of a project, you can most probably create, read/browse (either one Project or all projects), update, or delete projects. These are associated with views, which you'll learn at some point. Title, description, and plan_action are put into Models, which are usually saved in your database. Again, I recommend reading the guides and watching Zombies first so you get some information on how Rails works.