Hello Waishidesu,
Welcome to Apple Support Communities. It appears that your new iPhone 11 has vertical lines on the screen that disappear and reappear. In this situation, we suggest completing the following steps to determine if this issue could be related to the hardware:
1. Restart your iPhone or iPad.
2. Make sure that your screen is clean and free of any debris or water.
3. Disconnect any Lightning or USB-C accessories. If your screen works after removing an accessory, try using a different outlet, cable, or charger.
4. Remove any cases or screen protectors.
More details found here: If the screen isn't working on your iPhone or iPad
If you continue to experience the same behavior, you may want to return the phone back to the point of sale. You can also reach out to Apple directly using this link: Get Support
Best wishes!