Shopify doesn't require a business license, but it is strongly recommended to check with your legislation office if you still need one by law.
In terms of tax information and how to set them up in your store, we have a great guide here. You'll need to determine whether you need to charge taxes, and where you need to charge them, by consulting and register with the relevant tax agencies. There's some Florida state-specific tax information here that may help.
I hope this is useful, let me know if you have any other questions.
All the best, Hyde.
Andrew | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog