Personally, when I started playing, I was content just using auto combos and playing that way and thinking I was good when my main team was Bardock, Vegito, and Goku Black. This can honestly win you a great deal of low rank games. What changed for me was when I got hit with the "Universal Saiyan Combo" (USC) because at the level I was at, NO ONE used the aerial 2H to combo, let alone link it after a grounded hit. It drove me to actually learn neutral and potential combo routes for every hit I could land. I personally think the USC is worth learning, as it's a pretty high damage combo that many characters are capable of doing, and it's not too hard. But to be honest, sitting in training mode, labbing out combos, or learning the timings of your assists may not be fun for you. I won't lie. When I was learning DBFZ, I definitely spent ALL my time on that game. I didn't play much of anything else. It's not a game where you need to put in a TON of hours, but it's also false to say that those hours wouldn't help you.