You can change your business type industry if you're using either QuickBooks Desktop Premier and Enterprise editions. To do this, please follow the steps below:
At the top menu bar, select Help.
Go to Manage my License.
Click Change to a Different Industry Edition.
For additional reference, you can check this article for the detailed steps on how you can change your QuickBooks Desktop edition from a specific industry to another: Toggle to another QuickBooks edition.
Please know that you're always welcome to post if you have any other concerns. I'm always here to help. Have a good day!
Re: Can I change my company from service-based to product-based?
At this time, changing your company from service-based to product-based isn't possible in QuickBooks Pro. I'll make sure to pass this along to our Product Developers Team to let them know how this is useful for your business.
You can also check for any updates on the Customer Resource Center page.
I have this Help Articles in case you have other questions about QuickBooks Dekstop.
Keep in touch if you need anything else. I'm always right here to help.