Hello @CindyTilley and I wish you welcome to our beloved Candy Crush Friends Community!
There are actually a few main uses for Gold Bars within the Candy Crush Friends Saga game. The first being purchases of boosts within a level. The second is purchases of additional moves when you run out. Finally, you may use gold bars to purchase an additional 5 lives when you run out.
I hope this information was helpful to you, and I hope you have a crushtastic day!