Is there a quicker way to check all 6k of songs on my ipod or do i have to do them 1 by 1

In iTunes, you can highlight as many tracks (songs) as you want, right click the group and select Check Selection for all of them.

To highlight multiple tracks, click one then Control-Click the next, or click then Shift click to select all tracks between two clicked points, or use Control-A (select all) to select all tracks. The right click on the group and select Check Selection.

If you happen to select some tracks that are checked and some that are unchecked, when you right click you will see both choices, Check Selection and Uncheck Selection.