If you would like to sell certain products at an event that has different tax rates than your retail store, you can do so by creating separate:
Product categories
Products
Taxes
Event Product Categories
First, create dedicated product categories for the event. For example, if you would like to sell Flowers and Edibles at the Hall of Flowers, you can make categories for 'HOF Flowers' and 'HOF Edibles'
Event Products
For any products you'd like to sell at the event, you should make event specific product listings. For example, you can have a 'Chocolate Bar' to sell in store and a 'HOF Chocolate Bar' to sell at Hall of Flowers.
Event Taxes
Lastly, you should re-do all of your taxes AFTER YOUR STORE CLOSES (to prevent and orders with no tax or double taxes while you are changing the tax settings).
Delete your current taxes (after taking a photo of the settings for each)
Re-create each tax but exclude each event product category (make sure to click the 'Add' button for each category)
Create each tax you want to charge at the event
If the event has taxes included (for example $2 samples), enable the setting to 'Include taxes in price of products'
Exclude all product categories that are not for the event
When this is all done, you should have your in-store tax that excludes all event categories and your event taxes that exclude all of your normal in-store categories. Reach out in the support chat if you have any questions about this!