I am confuse about why Visual Studio 2017 doesn’t let me add HTML elements into the Default.aspx, but what I do know is that under the Solution Explorer, I see master page and apparently they are bind to the content page (which is the Default.aspx). Also, I put a copy of my screenshots problems.
So my question is do I start putting content (HTML elements) inside of that master page first!
Aside from what I have mentioned above, I also notice that when I try to put basic HTML elements into the @page directive (Default.aspx file), it says "“Content is not supported outside of ‘script’ or ‘asp:Content’ Regions” ".
The only reason I know of these terms is because I research this problem. Here are the articles that I have researched. “Content Not Supposed to Be Outside ‘Script’ or ‘asp:Content’ Regions” https://msdn.microsoft.com/en-us/library/wtxbf3hh(v=vs.100).aspx
Here are the screenshots of master page and default.aspx files.