there is a metal piece at the end of the handlebars that covers the end so the grip wont slide off, one of mine came loose and went flying off on the freeway, what would that part be called, and where would be a good place to get it please??

 

It is a bar end. You can find them anywhere motorcycle stuff is sold. Might be tough to find a match for the one you had, unless it was stock. You can grab a set off eBay pretty cheap.

 

You don't really want to buy the cheap ebay stuff to replace the stock bar end. The stock ones are much heavier than the ones you can find on ebay. They don't just protect the handle, but also were tuned to absorb the vibration from the fork.