The easiest way to create a Blazor project (assuming that you've kept your version of Visual Studio 2017 up-to-date) is to use File | New | Project, pick the ASP.NET Core Web Application project type, ...

Microsoft Visual Studio is your gateway to a career in software development. With its comprehensive tools, you can become a front-end, back-end, or full-stack developer, or even dive into data ...

An HTML Helper is a bit of Razor code that can be called from multiple places in a View. But, if you put your Helper in the right place, you can also use it from any View in your application.