Playing is counterproductive until you have some basic skill, but a little playing will keep you motivated and may show you things to be aware of unless the other player is also a beginner.
Do NOT do chess problems. They will not help at all and waste time.
Do not play blitz at all. Play 10-15 minute games but pace yourself to move in exactly ten seconds.
Reading books is good. You wont get much out of My System but it wont hurt you. You need to find and do tactical problems that are graded from easy to hard and are grouped around the same theme. See an example then solve ten more of the same type solution.
You need to learn ONE opening really well for white and black. But make sure it is ONLY ONE opening. Do not try to do more than that. Obviously there will be variations depending how the opponent plays that will already stretch your ability to master yet.
Eventually you will need to understand positional play and some other things but start with the list above.