To begin working on an order, you must "Claim" the order for yourself.
If you aren't able to view the order in your order list, you may need to ask another user (either the customer or current claimant) to SHARE the order with you.
Navigate to the "people" tab on the order.
You should see "Claim" listed at the top of the shared people list.
Once the order has been claimed the Claiming user will be listed with an "Un-Claim" button displayed: