I'm an absolute beginner and I am reading the guide on how to build an altcoin (forked from litecoin) here and I am confused on the first steps. I don't want someone else to do it, I want myself to do it. Can someone tell me how to do that using VS Community 2017?
Build environment: the environment in which the source code is compiled and built into a complete binary which you can run. This typically consists of the compiler, linker, OS you are building on, and OS you want the binaries to be built for.
Library: A library is a set of code that your or other's programs use. They are compiled just like any other program but they do not contain
main functions so it cannot be run as its own executable. Libraries are used to avoid code duplication for things that can be used across multiple programs.
Compiling: The process of turning source code into an executable binary. You must compile source code in order to actually use it.
Can someone tell me how to do that using VS Community 2017?
You really shouldn't do that. Bitcoin Core, which most altcoins' primary software (including Litecoin) are based off of, is designed for being build in a Unix environment (primarily Linux and MacOS). It is substantially more difficult to build it in a Windows environment, particularly with the tools that Microsoft provides (e.g. Visual Studio). It is instead recommended that you use the Windows Subsystem for Linux. Instructions for doing that are available here