How can I sign up with Apple Configurator 2

You don't sign up. You download it for free from the Mac App Store.

Follow these steps:

1. Login to the Mac computer and launch the Apple Configurator 2 (AC2) app.
2. Connect the device(s) to be configured to the Mac using the USB cable.
3. In AC2, select the iOS device you wish to configure, then click on Actions | Prepare... to launch the wizard.
4. Since AC2 can be used to prepare devices for MDM use, we are prompted with the Configuration type on the first page of the wizard. For the purposes of this article and since we are not configuring the device for MDM management, select Manual from the drop-down menu, then click the Next button.
5. On the next page, you'll be prompted to select the server to manage the device with post-AC2. Again, we will not be enrolling this device in an MDM, so we will select Do not enroll in MDM from the drop-down menu and click the Next button to proceed.
6. On the Supervise Devices page, you will be prompted to check the box next to Supervise devices, which enables supervision on that device. Additionally, if you wish to allow supervised devices to pair with their computers, check the box to allow that functionality. Otherwise, supervised devices will be disallowed from pairing with computers. Click the Next button to continue.
7. If you wish to enter information about the organization, you may do so on the following page. Enter the desired details and click the Next button.
8. When working with supervised devices, supervision identities are required. If setting up supervised devices for the first time, select the radio button next to Generate a New Supervision Identity to create a new one for your organization, then click Next to continue.
9. On the final page of the wizard, you will be prompted with choosing what options are presented to the end user during the Setup Assistant portion after the device is initialized. While optional, it is recommended that admins configure this portion by placing a check mark in the box next to each item you wish to allow the end user to configure--any boxes not checked will restrict end users from configuring those options during the Setup Assistant phase. Once these choices are configured, click the Prepare button to erase the device and reboot it in its newly supervised mode.

I hope this helps!

Courtesy: TechRepublic article.

It's free and download it on your Mac.