making an added page i.e “about page” my defalt index page?

Right now as it is the default page is the blog section of the site. I’d like to accomplish two things. I’ve created an “about” page that has a simple bio that I want as the main “index” page or home page. this will be the first thing people see when then type my url in.

second, I’d like to be able to split my blog into three groups or “categories” film, broadcast, and design, and hide the main blog so that the view will not see all categories clumped together into one long thread.

can anyone help a noob WP user out!

thanks