Going to vegas and staying at the excalibur, whats the best way i can shuttle/transfer for free and get back?

im vacationing in vegas for 4 days and was just looking for the best way to transfer to and from each casino from the excalibur hotel. im just looking to figure out the best transit system thats free and can get me to the north side of the strip like gold nugget and back. and make stops along the way..