Official SDK for macOS (make sure to pick the right one, arm64 or x64): https://dotnet.microsoft.com/en-us/download/dotnet/7.0

Then, an IDE of your preference:

- VS Code: install C# extension and Roslynator (it adds useful analyzers)

- Rider: provides everything out of box, is more user-friendly (especially for people who used to big and fully-fledged solution) and has much superior debugging capabilities but is paid and has higher memory and battery consumption