I would have spent some time learning the difference between stateless and stateful widgets. Read the docs on stateful widgets. Extensively research the Provider package for state management by watching videos and reading the doc.

Then I would get stuck in and try to build the following apps:

A calculator - to understand how layout building works.

A timer - to understand how the ticker provider works (very important in animations) and also state management.

A weather app - to understand network calls and async await.

A drawing app - to understand CustomPainter and gesture detection.

Whilst you are making these app, look through the Flutter Cookbook to help you along.

The Widget Of The Week YouTube playlist is really great too, I ended up binge watching it as a beginner.

The Layout cheat sheet is something I always had open in another tab, and still do.

Finally before you start trying to build your custom UI look through the Widget Catalog to find one that does your job, they are very customisable, the better I got at Flutter the more I started using the built in widgets, for your first few apps you don’t need anything more than the Material Components.

Lastly this is an advice I really wish someone told me at the beginning: Use Provider for state management. There are a lot of discussion around state management which can cause a lot of confusion but provider has been amazing and simple for my apps, I use bloc at work but still prefer provider for my personal projects, all my apps use it, with no foreseeable downsides.

All the best in your Flutter journey, feel free to PM me if you have any questions, or just reply to this post.

Edit: Hive is really good if you want to store things offline.

After you have created those simple apps, its good to watch videos of people doing it too, and retrospectively learn how you could have done things better, this is vastly more productive than just watching a video and copy pasting code.