I am fairly new with flutter and am trying to create a application that doesn't follow the material design guidelines(company wants their own designs).
I can only seem to create stuff using material design or cupertino. I am not sure how to use custom scaffolds or in the widget build function return new MaterialApp(..., or the AppBar if that can be flat instead of having a shadow.
I hope this is making sense. I am just trying to find a way around.
There is no problem with not using Cupertino/Material design. In fact flutter is made with custom brand design in mind. It just happens to ship a Material design as bonus.
Flutter provides tons of design agnostics widgets that you can use to make your custom look. A few examples are:
You can also make some very advanced rendering using the lower layer CustomPaint or RenderBox
You can have a list of what's available here: https://docs.flutter.dev/flutter/widgets/widgets-library.html