Should I use Magic Lantern as a beginner?
As someone who just went through the transition of using Canon firmware to Magic Lantern firmware, no. It depends ENTIRELY on what you know. For instance, do you know what shutter speed, ISO, and aperture are? Do you know what effect shooting "wide open" or with a high ISO has on your shot? Do you know how to correctly set your white balance and get correct exposure? 

If you're a beginner and you're not familiar with these terms, you may at first be overwhelmed; that's totally normal and OK. But, it is my strong suggestion that you get to know these things and work with the standard Canon firmware before moving to Magic Lantern. Film making is hard enough as it is, no point in making it more difficult on yourself. Once you have a strong grasp of the basics, you can better appreciate/utilize the features that Magic Lantern gives you (recording formats, focus peaking, settings logs, RGB parade, hotkeys, wider range of ISO/aperture values, etc.).