Good structure and design patterns to use in a solution

So I'm asking myself this for some months now. I was learning programming in java, but right now I working with C# webforms. and I also studied C# MVC .NET for some time. The structure and desing pattern for these are different, My java teacher use lots of abstract classes and interfaces, factory design and some others. But the at my work some C# developers with more then 5 years experience said they rarely see that in C# projects. So lately I decided to study and practice ASP.NET CORE C# with future in mind, using git, mvc structure, unit tests, and right now I trying to decide with design-patter use in my aplication. https://github.com/guilherme1301703/SimpleRPG/tree/develop

So guys, for the years that are coming, I decided to use asp.net core C#, but what kind structure, desing-patterns or technologies inside this is good to start learning or using, with focus in good practices and develop speed?