Q: How polish front panel first gen ipod nano?!

For the clear plastic surface of older iPods, you can use a mildly abrasive polisher with a soft cloth.  An off-the-shelf household item you can use for this is toothpaste.  There are also special "kits" made for this purpose, for example

http://eshop.macsales.com/item/NewerTech/NEWPOLISH/

They usually come with three polishers.  One is more abrasive, that you use first if the item is badly scratched up.  If the item only has many fine scratches, you can skip this one.  The second one is less abrasive, for finer scratches.  And the final one is like Windex or eyeglass cleaner, to dissolve and clean off the residue (not really a "polisher").  It's the first two that do all the work of polishing.

The best cloth is the type sold for cleaning eyeglasses ("microfiber").  But I've used old cotton t-shirts that I would otherwise throw away.  It should be a soft cloth with fine fibers.

Be careful not to get the polishing cream or liquid into the seams of the click-wheel.  Do not use abrasive polishers as a cleaner; if the iPod was previously in good shape, you'll end up with many ultra-fine scratches (which may or may not be an improvement).