I don’t want to enjoy Rocket League, I want to enjoy Mario Strikers: Battle League! =P
I basically never fail to enjoy Nintendo games so this is an unusual and frustrating case for me. I feel like I’m missing something, ‘cause even the basic act of controlling and keeping track of the game just isn’t clicking for me.
Strikers has always had a skill floor that isn't quite as low as in other Mario Sports titles because you're controlling a full team with controls that change depending on whether you have the ball or not, though Battle League might take the longest to adjust to because of how different it is to the other entries. In the first game it was a lot more spaced out and simplified, while in Charged there was a very overt loop to ball handling that had more simple appeal (chain passes to charge up and shoot). In Battle League, the playing field is a tad smaller, the game has stamina features, and there's a few more commands to work with. Not helping matters for newcomers is that items bring about a degree of threat and chaotic claustrophobia, and combine it with the default 2v2 mode with randoms in this demo, and it's about as overwhelming as being a first timer thrown into a Smash Bros. trial by fire in Hyrule Castle with all items on.
Readability in Battle League is a bit tricky, but basically I'd recommend paying less attention to the ball itself and more to the circle. I would also suggest switching control mode to Auto to make life way easier for you when doing passes, The biggest hurdle in 2v2 is generally knowing who you're in control over, but the Auto function alleviates things by making it so that anytime you pass, you'll switch control over to the other character assuming they're CPU controlled. To that end I'd recommend trying to stick to one character as much as possible. It's likely you might lose a few rounds since maybe you'll have relented on opportunities when you can swap over to another character and tackle them, but I think the important part is just getting a feel for your own character and the tackle/dodge process. Switching on the visual assist won't alleviate the visibility entirely but it should at least give you a better idea of your overall location.
After that, I'd say take your time and see if you can get into a good groove. Things to keep in mind that doing fully charged tackles will stun you if you miss, so only do regular tackles until you get a proper hang of that. High strength characters like Waluigi and Bowser have an easier time playing this kind of role. Try focusing more on weaving and shooting when you're in ball possession, it might seem antithetical to team work but only pass if you're in rough spots. Try to set aside doing any of the more advanced techniques like through passes and team tackles until you feel comfortable just controlling the space surrounding one character. After that you can start experimenting more.
Of course, there's a good chance it won't click and I don't blame anyone if that doesn't happen, but it's quite a magical game when things come together, and if 2v2 isn't working out for you then hopefully the 1v1 gives you more breathing room to maneuver.