Hi there, Peter.
I'm here to assist you with achieving your goal of changing your subscription.
Each QuickBooks program is designed to address specific business needs. You can change your subscription from Self-Employed to QuickBooks Online or QuickBooks Desktop to manage your data under a corporation business entity.
To help you identify the right program that suits your business needs, you can check the article: Compare QuickBooks Online to Desktop.
In addition, I'm sharing these resources to learn your way around QuickBooks.
Get back to this thread if you need further help managing your account. I'll be sure to offer assistance.