Usually, source code are compress in the archive format, its either tar.gz (.tgz) or bz2.
The command uses to extract these archive is tar. Let say your archive is test.2.tar.gz.
You can decompress it and extract to your folder like this:
tar -xzvf xyz2.29.tar.gz -C /usr/src
*-C is to indicate tar where to store the extracted files.
Common open source programs source code comes with configure files and makefiles. Because those programs usually are cross platform compatible. That means it can be compile in different platform such as Unix, Linux, BSD etc, given the required library installed and the dependencies solved. Therefore, before start to compile and install, you usually need to configure.