Every state or every country has a different tax setting. If you are in an area where there is a single tax requirement, then you are in luck because it is definitely easier to set up than when you are required to charge multiple taxes.

Here's how to set up a single tax:

So how do you set it up? First, go to the Manage Taxes section in Settings > Store. Once you turn it on, you should see an option that says Choose Tax Rate. Choose the Single Tax option.

Then type your tax rate in the Enter Tax Rate field. For example, if your tax rate is 10%, just type 10 (without the percent sign) in the field. 

Then click the Save button.