Replace 'Hello World' w/ 'Sample Page'

you will generally have some heavy reading coming your way – most things are described in the codex.

http://codex.wordpress.org/New_To_WordPress_-_Where_to_Start

http://codex.wordpress.org/FAQ_Working_with_WordPress

replace the ‘Hello World’ post with the ‘Sample Page’ page

http://codex.wordpress.org/Creating_a_Static_Front_Page

not have an area for comments below it.

http://codex.wordpress.org/Settings_Discussion_Screen

there are further ‘discussion’ settings below the page editor; if these don’t show, click the ‘screen options’ tab near the top right on the ‘edit page’ page, and tick ‘discussion’ there; then scroll down to below the page editor to make the ‘discussion’ settings there.

general; get familiar with all the options and settings in the dashboard/admin area.

last but not least:
twenty ten will be overwritten with the next upgrade of your wordpress version; all modifications (of the theme template files) will be lost.
consider creating a child theme http://codex.wordpress.org/Child_Themes