First you have to comprehend why you think it is important. If you just "establish a rhythm" without realizing its purpose then you don't really benefit from it. As a simple example, if you go to quick matches you will find lots of newbie players who get intimidated easily and start backpedaling if you plod forward. If you try that with any competent player they will stand their ground and throw strikes. Then, if you think they will try to catch you walking in you can zig-zag in and out instead and make them whiff (a very common tactic in footsies).
Moreover, if you analyze "scrub" matches as you put it you will notice people doing this back-and-forth movement a lot but they're not doing as a response to their opponents' actions but instead it's their own arbitrary habit. Ideally you want to put your opponent vs the cage because then it's easier for you to control when you exchange and if they get rocked they can't retreat whereas you can. Hence, if you think your opponent is going to move back, you can simply walk forward to force them closer to the cage.
Similar ideas apply to what Ryangil and Zyaf talked about. Zyaf used 1, 1-2 as an example because it's a safe way to hit your opponent from distance and he then diverts to the other more damaging options when the opponent proves they're sentient and tries to counter the 1, 1-2. At scrub levels you can simplify it to mixing 1-2s with 1-4s (jab-rear hook) until you have a greater understanding of all the tools in the game IMO.
The problem with that is that it varies greatly depending who you play against so it is difficult to make a general guide on it. However, there are plenty of videos about reading patterns and counter-striking and they essentially cover similar aspects because what you're really asking about is pattern reading and setting up attacks.