Most likely you downloaded source code. That’s fine, but getting that to run is most likely not what you should be doing as a beginner. It gets complicated quickly. There’s no simple 3 step solution for that.
While I’m a developer, I’m hesitant to build software from source on my private laptop. I keep it tidy and stick to what’s in the repository.
The only thing else that should be simple to use are flatpaks.
What you have is a bz compressed archive. Depending on the tool, it is extracted in one or two steps. If you end up with a tar file, it needs to be extracted once more.