How do I remove calender link at the top header
and also how to I remove Languages list bar at the bottom footer?

By editing your skin templates... Though I think there is a setting for the latter.

skin templates to remove calender link and also Languages list bar at the bottom footer?

How do I remove calender link at the top header

All Global HTML -> global_board_header

Find and remove;

<a href="{ipb.script_url}act=calendar">{ipb.lang['tb_calendar']}</a>

and also how to I remove Languages list bar at the bottom footer?

All Global HTML -> global_lang_chooser

Remove all contents of that template.