Can you plot your question more clearly? As I can assume you said that you can't asp.net core web application. First, see if you had installed .net core framework on you machine. To check it WIN+R and search dotnet --version you will get the version. If the version is above 6, then it is dotnet core.

Moreover, If you can't find asp.net mvc application (.NET CORE) or asp.net mvc web api (.NET CORE), reinstall VS and add these Packages. I hope it helps.