Which subscription do I need? I am a dog walker and want to track my milage and expenses using my mobile phone.

You may start from QBSE

https://quickbooks.grsm.io/UK-SE

I can help you with choosing the right version of QuickBooks that you need, @aliciashouseofpa.

You can choose QuickBooks Self-Employed (QBSE) if you're either a freelancer, independent contractor, and service-based entrepreneur. It'll help you track your income, expenses, mileage, and tax info. QBSE also has a mobile app to keep you on the go. 

Here's everything that you need to know about QBSE: QuickBooks Self-Employed Overview. 

QuickBooks Online (QBO) is designed for small businesses. To check the comparison between those subscriptions, I suggest checking out this link: QuickBooks Online comparison.

QBO also has a mobile app. See the following article to check the features available in the app: Compare mobile app features. 

This article will walk you through getting started with QBO: Get started with QuickBooks Online.

You can always leave a reply below if you need further help in choosing the right version of QuickBooks for you. Take care and have a great rest of the day!