Is ASP.NET CORE 2.0 Worth Learning?

Question

Recently MSFT released ASP.NET CORE 2.0. But with the announcement of .net core 3.0 in asp.net it will only support .net core framework not .net framework as it is supporting upto 2.2 version. Since number of projects will be made using ,net core 2.0 or 2.2 , so how it will be for those who developed using .net core 2.0/2.2 in terms of porting, or supporting. Or will developers need to rewrite the whole web apps in .net core 3.0. Please provide answer since  I m planning to develop an web app using ASP.NET core in next month after learning ASP.NET CORE. And also suggest which version of framework to use so that It will be easier to upgrade or compatible with future releases.