Hi there,
Welcome to the Community. QuickBooks offers a powerful tax module that simplifies the way you manage your taxes. I'll be happy to share info and steer you in the right direction.
Once you've set up your taxes on your account, you can begin to use the tax codes so QuickBooks can keep record of your taxes. I encourage you to check out this article here that shows you how to set up sales tax. The program also makes it easy for you to file your sales tax. Here's a helpful article that shows you how to: File sales tax in QuickBooks Online.
In case you're experiencing browser-related issues, I recommend clearing cache and cookies on your browser. Clearing cache and cookies is a great way to clean your browser allowing it to work more efficiently. Here's an article that shows you how to do that: How to clear cache and cookies.
You're welcome to ask other questions. I'm here to steer you in the right direction.