Unfortunately, FeedBurner cannot generate feeds for websites that do not currently produce them. Virtually all blogs created by systems like Blogger and TypePad create their own 'standard' feeds which FeedBurner can locate and then use to create a FeedBurner feed.
If you want to try to 'autogenerate' a feed from your existing website's content, you may need to use an application like FeedForAll. Alternatively, you may consider creating a blog using Blogger or another publishing service, and then use the automatically-created feed that is associated with your new blog with FeedBurner. Any content updates you publish in this new blog will automatically end up in your FeedBurner feed, and it may be easier to use this 'new' site to publish updates than to try to redesign an existing site to accommodate feeds.