A custom image belongs only to your project. To create an instance with a custom image, you must first have a custom image.
Reference:
Preparing your instance for an image
You can create an image from a disk even while it is attached to a running VM instance. However, your image will be more reliable if you put the instance in a state that is easier for the image to capture. Use one of the following processes to prepare your boot disk for the image:
Stop the instance so that it can shut down and stop writing any data to the persistent disk.
If you can't stop your instance before you create the image, minimize the amount of writes to the disk and sync your file system.
Pause apps or operating system processes that write data to that persistent disk.
Run an app flush to disk if necessary. For example, MySQL has a FLUSH statement. Other apps might have similar processes.
Stop your apps from writing to your persistent disk.
Run sudo sync.
After you prepare the instance, create the image.
https://cloud.google.com/compute/docs/images/create-delete-deprecate-private-images#prepare_instance_for_image