@Sofia34 As an Airbnb host there are 2 types of taxes you need to consider. One is Federal and State Income taxes. By tax filing date you are expected to report Airbnb rental income to the IRS and to the State of California.
The other type of tax is called Occupancy Tax which is levied by the county in which your listing is situated. I assume that your qustion is about Occupancy Taxes, yes?
If so, then you have 2 choices: incorporate it into your nightly rate or ask the guest to pay at check in. I incorporate it into my nightly rate because I think it would be awkward to ask the guest to pay separately. I report and pay it monthly based on my gross earnings (before Airbnb takes its 3%). Here's what Airbnb has to say about it:
https://www.airbnb.co.uk/help/article/654/what-is-occupancy-tax--do-i-need-to-collect-or-pay-it
Hope this clarifies things for you.