How do I change my QuickBooks to work from April to April instead of January to January ? I’m on the app using an iPhone

I've got you covered, @userkieranblackwood1.

You can change your company set up using a browser. Follow along below to get this done right away:

1. Head to the QuickBooks sign in page at this link. 
2. Go to the Gear icon and choose Account and Settings.
3. Click Advanced, then select the Accounting section.
4. From the First month of financial year option choose April.
5. Under the First month of tax year drop-down pick Same as financial year.
6. Once done, hit Save.  

For more info about the process, refer to this article: How do I set my advanced account settings?

I've also added this great source where you can find articles that can help you in managing your books in QuickBooks, please head to QBO help articles at this link. This includes topics such as reconciliation, track income, and expenses, run reports, etc.

Please be sure to check back in with if you have further question about this. I'm always around to help you in any way I can. Have a good one.