As a business, you may have requirements to pay sales and use tax if you sell goods. If you sell services, you typically don’t need to worry about sales and use tax, but it depends on the state rules. Some service providers (e.g. construction) may need to pay sales and use tax if an item (e.g. fabrication costs) is “sold” to the customer as part of the delivered service.
There are also complex rules concerning sales taxes for online sellers. Check with your state for specific regulations.