Trouble understanding the momentum and pressure game of Street Fighter 5

Hi there, I am new to the street fighter franchise. I played persona 4 ultimax, blazblue,mortal kombat x, and guilty gear xrd competitively and I went to Ceo, Acen and for mortal kombat x I went to a few local tournaments and won my fair share.

The main point here is that I want to ask how to penetrate/ break through different character styles specifically in street fighter 5. I have a strong interest in Chun Li and I plan to make her my main character but I myself am not even sure how she is defined because she has some skills of a shoto but they are definitely not as refined as say ryu.

-How do I tell What is a hard knock down ?
-What do I do with a hard knock down?
-What is the exact timing for a quick recovery(I can’t do it or I keep doing it on hard knockdown?) the input is double punch or double kick
-What moves are notable and important for chun li as in anti airs ?
-What is the main focus for playing chun Li?

If anyone could point me towards a video that isn’t for absolute beginner or any information that would be for people who are more versed in fighting games. What Should I study to get better?

Watch Amir play Chu-Li n in the SFV Beta to get an idea of how to play her. Look at his archives for the vid.