Build a PowerApp

I need a Canvass PowerApp within my company's Microsoft 365 account where an employee can view their previously submitted leave and travel data, and then edit/ update both of these datasets. Currently, the team uses two excel sheets on OneDrive for both of these datasets.

I'm not sure if this is possible because I cannot provide the login to my company's 365 account, but I can upload apps. So you would have to build the app, and I would upload it and connect it to the datasources in the Business Onedrive

This app would be a total of 6 or 7 screens, so fairly simple. I built out a basic structure, but I don't know how to code it to make the data editable.

I need the app to show the user only their data, and allow them to edit it in a grid. I have the historical leave and travel data in an excel sheet on OneDrive. The app can either connect to this data, or I can upload it into the App. This data just needs to be exportable in Excel… so maybe a location on Onedrive is best. And I don’t mind starting a brand new dataset… I can manually enter in the historical data to populate the app initially. And then I need all of this data exportable so it can be analyzed

I can provide the data and a Powerpoint explaining how I want the app built. I uploaded one screenshot explaining the editable grid in the PowerApp.