I would suggest just making games. Test your skills with those tools to make a small game from start to finish; focus on the aspects that you'd want to showcase to an employer (do you want to be an artist? make the art stand out!).
Each position you apply for is going to want different things, but most of them don't want just "experience with x", they want "experience developing with x" (meaning working on a project as a whole, and often time shipping the project).
The absolute most surefire way (that may be an exaggeration) to find out what you need to do to get a job in game development is to look at job-postings (there are a lot of game-dev jobs posted on job boards on the internet) and look at what they want.