I did a video on what I would do if I was starting from the beginning and learning SwiftUI and Combine again. The focus is using the Apple provided tutorial/WWDC content to start on a solid basis...
Apple SwiftUI Landmarks Tutorial: https://developer.apple.com/tutorials/swiftui/
WWDC 2020 Data Essentials In SwiftUI WWDC 2020: https://developer.apple.com/videos/play/wwdc2020/10
Once you've done those I would recommend moving on to build your own simple app using the concepts you have learnt. If you need inspiration Kavsoft on YouTube is a good channel to see what components produce different UI results
If you get stuck head to Hacking With Swift for an answer. You can also do the 100 days of SwiftUI on the website if you want to take it more slowly or are a newcomer to Swift itself
A great blog covering all aspects of SwiftUI (and Combine) is Swift With Majid and I'd throughly recommend checking it out.
In terms of Combine there is a great free/donations book - https://heckj.github.io/swiftui-notes/ - this covers all the basics and will give you a good grounding in how to approach Combine
If you are looking for something more example based I recommend Practical Combine by Donny Wals and his blog is filled with great Combine related articles and more
Watch the orginal video here: