Hi there,
It's great to learn you're using QuickBooks to help manage your mileage for your business. I'll be glad to share more info and help steer you in the right direction so you can achieve your QuickBooks goals.
You can manage your mileage using a web-browser on your computer. In order to do this, click on Expenses from your QuickBooks dashboard and navigate to Mileage. I encourage you to check out this article here as it provides more info on how to track your mileage.
Feel free to ask other questions as you browse through the article. I'll be a message away in case you need further support.