Can I number songs on an extra playlist??

Numbered where?

The numbers adjacent to song titles in a playlist simply indicate its position in the list as it is displayed. It's not a fixed number. For example, look at the three screenshots included here that show the same playlist:

In the screenshot above, the list is in the order that the list was created and modified and I know that because of the arrow in the column header above the numbers.

Now compare that with the next screenshot:

In the screenshot above, the numbering is still the same, but the songs are in reverse alphabetical order. Again, the arrow in the Name column header above shows the Sort Order.

Finally, the screenshot below shows the same Sort Order as the first screenshot, but the song order is now different:

In the first screenshot, the track titled Acropolis Falls was number 2 in the list. Now it's number 3 and that's because I have manually dragged it into the third position. Dragging tracks into a different position is only possible when the playlist is sorted in forward or reverse Number Order.