iPhone apps can only be loaded via usb from a Mac. As they can only be built on a Mac, this is not typically an issue. To load iPhone apps via usb, you until Xcode which includes the side loading and debugging tools.
You can also use a Mac as 5he main development as it supports both iOS and android. Look at visual studio for Mac.
Note: your Mac o/s is probably too old. The latest tools and builds for the latest IOS will only run on Monterey
Apple is a little harsher with developers. The latest Xcode and iOS simulators only run Monterey. So to build for current iOS versions you need Monterey.
You need a late 2014 mini to run Monterey. Might be time to upgrade.
Your only other option is a cloud build and test flight deployment. This will work, but you will not be able to debug.