Hello and welcome to the QuickBooks Community!
It sounds like you'd like to start using QuickBooks to track your mileage. You've made a fantastic choice using QuickBooks Self-Employed for this - all you have to do is get things set up, turn on the app and QuickBooks takes care of the rest. Let me go over this with you.
When setting up mileage tracking and vehicles in QuickBooks Self-Employed it's important to add your vehicles that you'll be using prior to tracking mileage. When you enter your vehicle, QuickBooks prompts you to enter a variety of information, such as make and model, year, cost, etc. It also asks you for information on how you want to record mileage for this vehicle. Until you've entered at least the make and model QuickBooks won't allow you to save the vehicle. Once you've entered this information and completed the rest of the steps in the article linked above, you'll be able to start automatically tracking mileage.
If you forgot to open up QuickBooks on your trip, you also have the option to manually add trips into QuickBooks Self-Employed.
If you have any follow-up questions about this process, don't hesitate to reach out. I'm here to help.
