With a new battery and alternator there is little left as to why the battery is not charging. assuming you have connected uo the wires to the alternator correctly, having cleaned the battery terminals back to shiny metal and fitted the correct drive belt (most important) With the belt correctly tensioned the top of the belt should be level with the top of the edges of the pulleys. If it it is not then the belt will not drive the alternator fast enough to charge the battery