open your project, in the main window click the green add new button in the content browser, then click add feature or content pack. this will bring up a new window which lists all the templates, select the first person one and click add to project. thats how you can add the fps template to your project.
otherwise you could just modify the character you have now so you dont need to add all the other stuff.
or you could create a fps project then migrate the assets you need by selecting the asset in the content browser and right clicking it.