1) when somebody buys something off of the website there is no sales tax charged. If they are in the state of California then I need to charge sales tax. And depending on what county in California will determine the tax rate. Generally speaking the tax rate would be 9.25%.
2) if somebody buys more than one item of the same kind they only get charged shipping for one item rather than to shipping charges. The things that I ship are very heavy and expensive to ship so I need to charge for each item that they purchase.
I can learn from your requirement is you want to fix tax structure for different products with same or different rate and accordingly wants to modify invoice and the pricing you will show on digital platform.
I am Tax Accountant with more than 4 years of experience, I can help you to get things done as per your requirement all I need is little more details from your end.
you can message me for more details.