Add in about us text at homepage using Blogger Widget. Add a button or link easily using Bootstrap3 built in classes. An example is given at theme tutorial page.

This about us section uses Blogger Image Widget to add as a background & a HTML widget to insert the text.
Go crazy editing from Blogger Layout. Add text & links using the built-in text editor. Use Bootstrap classes to enhance buttons & links. Use font awesome classes to add in icons easily!