Copying foot and arm movements doesn’t mean you are doing things correctly. You need to learn to engage the right muscles to get you there. The only thing you will learn online is the actual dance steps but not How to dance. For that you need a qualified teacher’s eyes and hands on you for corrections. You also need a sprung or floating floor to work on like you would find in a reputable dance studio. Working on a floor with no “give” for any decent amount of time to gain any real skills (even if you had a qualified teacher there correcting you) and you will get injuries to your joints along with shin splints or even stress fractures.
If you want to learn to dance properly in order to get better you need to take classes with a qualified teacher. If you are worried about you lack of skills there are many beginner classes for teens.