you can use an empty template and add your own fragments for the old way, but i suggest using the content_main.xml as there has to be a reason whey android is implementing it with a blank activity. as long as you leave the 'include' tag in the activity_main and but your views(textview, button, etc) in the content_main.xml. i havent found suffectient reasoning for this extra layout but, as a new android developer, i will be using it in an assumption that it is, will be, best practice. as far as tutorials not being current with this method... i just add my views and/or fragments to the content_main. youll also come across tutoriald with depricated code. omg, this was so frustating for me at first, but chances are youre not the first to realize this and a quick google search will usually show you the alternative. also i suggest learning with the free udacity/google course. simply put... its great.
heres a link to the udacity/google course. dont click the 'start free trial' click the button below that which says 'course materials'. these people are very thorough and provide updated code for each step of each lesson. some classes used are deprecated but they try to let you know if theres a better way OR if not, you can usually find help in the comments for the lesson's code.
https://www.udacity.com/course/developing-android-apps--ud853