Hi Garrett,
As I understand you already have Photoshop subscription and want to know how what will happen if you wish to purchase Creative Cloud all apps plan.
You can visit this link and upgrade your plan from Photoshop to all apps and in this case, no cancellation is required. It will directly change your plan. Link: Learn how to change your Adobe Creative Cloud plan
If this link does not work, you will have to first cancel your subscription and purchase it again from our website. Please see the links below:
Cancel: How to cancel your Adobe Creative Cloud plan or membership
Purchase: Creative Cloud pricing and membership plans | Adobe Creative Cloud
You may also Contact Customer Care for help and support.
Feel free to update the thread for more questions.
Thanks
Kanika