Looking for Tips for Debugging and Developing web pages

Question

I have a a couple of tasks.  Both are web based projects.  One has to be attached to a running browser running a local host based app.  The other one I have found I can run directly through the browser.

 

The first thing I would like to discuss is what would make these two projets different so that they can only be tested and debugged differently.

 

The next thing I would like tips on is this.  How does one debug actual html code in visual studio?  Is this even possible?