What Causes A CD To Skip On The First Song On Every CD On My Home CD Changer.?

Dirt on the lens can't be the cause.

Have the pickup "sled" serviced at an audio repair shop.

It probably needs the lens cleaning, or it is simply worn out - the lasers and mechanics can fail over time.

Example lens cleaners:
http://www.ebay.co.uk/itm/like/401159805951?lpid=122&chn=ps&adgroupid=36084540643&rlsatarget=pla-266373412027&adtype=pla&poi=&googleloc=1006828&device=c&campaignid=698615505&crdt=0

https://www.amazon.com/Memorex-DVD-Lens-Cleaning-Kit/dp/B00008EM7U

http://www.currys.co.uk/gbuk/computing-accessories/computer-accessories/pc-cleaning/essentials-multimedia-laser-lens-cleaner-10209405-pdt.html