Hello ! You can only accept one contract at a time, which is why the others disappear once you've selected one. When you accept a contract, you’ll receive a piece of paper in your inventory that contains the contract details. You’ll also see a black "X" marked on your map—that’s the exact location you need to go to in order to complete the contract.

Once you've completed the objective, return to the computer and go to the "Contract" section to get paid. If needed, you can also cancel the active contract from the same menu.

Hope that helps!

@Raixxar The info was very helpful thank you and it was also user error on my part. I thought receiving quest info was as instantaneous as clicking through the rest of the options. I now know you have to wait for the dialog to start after clicking.

However, now I have a new issue.

I've completed the quest, returned to the contracts section to finalize it, but I can't. I'm only given the option to cancel it. The Quest was to kill 50 Zombies. I've killed 57.

Is there a step I've missed?

-Thanks again for helping me with this.