I just finished learning c# here in sololearn, so what should i do next?

Answer 1

Start learning a framework, so you can build real world apps with .Net like Xamarin ( for mobile apps, or MAUI ), ASP .Net Core ( for web apps ), WinForms ( for desktop windows Apps), Games ( with Engines like Unity3D and Cry engine ) and plenty more other applications....

For more information visit https://dotnet.microsoft.com/

Answer 2

learn some libraries to make real applications that you see in the market(internet)