You must have your Disneyland ticket in order to enter the park. You must also have the ticket to get FastPass tickets. Because this ticket is so important, it needs to be kept in a safe place. Along with the Disneyland ticket, you also need a safe place to keep money or the Disneyland Merchandise Card.
A wallet or purse is not very practical at Disneyland. Instead, you should purchase a FastPass holder even if you dont get any FastPasses. This is a small plastic pouch that hangs from a cord, which is worn around the neck. These can be purchased at Disneyland, and they are very inexpensive.
If you think you might not want to spend a little bit of money on the FastPass holder, you should consider what a new Disneyland ticket will cost. If you lose your Disneyland ticket, you will not be allowed to enter the park the next day without purchasing a new ticket. When you look at the small cost of the Disneyland FastPass holder, you will see that it is well worth it.