I'm not sure exactly what your question is. If you're not sure how to start making a site, it's quite simple. Go to File -> New -> Web Site -> ASP.NET Web Site. Your 'Default.aspx' is basically the same thing as an 'index.html,' in that it's the first page people will see. You can also right click on your project to add more .aspx pages as you need them.
A .aspx page can be edited just like an html page, and you can use any html elements inside of it. Further more, you can also attach CSS stylesheets, java, etc... If you're not sure what I'm talking about, I'd suggest reading up on html and the basic web languages, they're quite simple really. Last but not least, I'd suggest reading up on ASP.NET in general to see how things were via client and server relations. Here's a good site for that: http://www.w3schools.com/
Please mark your thread as solved if your questions have been answered :)