Apple has many excellent free learning resources: https://developer.apple.com/learn/

This Udemy course is good: iOS 17, SwiftUI 5, & Swift 5.9: Build iOS Apps From Scratch https://www.udemy.com/course/ios-15-app-development-with-swiftui-3-and-swift-5/

Udemy regularly changes the prices of their courses - I’ve seen the same course from under $30 to over $200 in the same week. https://www.reddit.com/r/learnprogramming/comments/15jgm6z/whats_up_with_these_ridiculous_udemy_prices/