To add this:
https://en.wiktionary.org/wiki/Appendix:Glossary_of_fighting_games
(I wish I could find a proper site to help you out more)
This full list of Fundamentals will help you out of how to play the fighting games, such as Mortal Kombat, properly. If you read this, you will understand how things work out here in the Fighting Game world. If you were into a martial art, then consider the fundamentals as the most basic stuff in martial arts. Note that the move inputs in Mortal Kombat are different from the other fighting games, so ask around to help you understand what any input means and how to think of this accordingly.
After reading the fundamentals, go train with Lasher Takeda. You can ask around in these forums:
https://testyourmight.com/forums/takahashi-takeda.428/ to help you out with Lasher Takeda. Or if you ever pick Sub Zero, here are these forums:
https://testyourmight.com/forums/sub-zero.403/ .
So do yourself a favor and stop playing the online games for a while. To make yourself a pro like the rest of us, you need to train with your character, have a certain mindset to know how to deal with each opponent, meaning to have a tactical and strategical mind, and have good reactions and reads. To acquire them, you need to find good players in your country to train you and explain you how things work, such you need to tell us where you are from, so that we may help you out.
In this video, what you showed was the bad read. A good read is to see your opponent's animation doing a punch or a kick, so you know where you need to block (high or low). A good reaction is to know how to evade a dangerous move or doing a counterattack (in Mortal Kombat X, as of the last patch the counterattack is now dubbed Kounter).
It will take you awhile to get used to it. If you learn your character's moves, and then watching Takeda's combo videos in Youtube, you will most likely recognize the moves and think of your own combos, like every pro do.