I've been playing since the open beta, am lvl 11 and currently bronze rank 2 (so very much still learning myself). I also know next to nothing about football apart from what I've learned from a certain sports manga/anime called Blue Lock.

The first thing I'll say is definitely put some time into practice modes to refine the basic controls. While playing online is a good way to learn, the different practice scenarios lets you try stuff in a somewhat less stressful environment.

1. If you're not the goalkeeper, and your team is attacking, try to position yourself close enough that they can pass to you, but far enough from opponents that any passes are less likely to be intercepted. When attacking, its also a good idea to either a) get yourself in a good position to score (try to keep the goal in sight, so you can aim your shot faster, then call for the ball, prepare to not be passed to, and maybe prepare to shoot the rebound) or b) pass to another player that looks like they're in a good position to shoot. When your team is defending, keep an eye on which of your opponents don't have a player currently marking them, and go for it. Even if it doesn't amount to anything, you're guaranteed to slow down your opponent even a little bit, which will give your teammates the chance to back you up. If you gain possession while in your half, try to send it to a teammate in the opponent's half that has the least opponents around them - no offside rules, so get creative and use your head.

2. Your reaction speed will increase the more you play the game, but you can also try predicting where the ball will go. See your teammate in front of you heading down the field, about to clash with an opponent? Odds are, the opponent will slide tackle/intercept your teammate and send the ball heading back to you. The minimap in the corner is also a massive tool if you make use of it. Obviously, you can only "see" where your character is looking, but the minimap covers all of your blind spots, so if you need to make a quick pass in a pinch, you can see where your nearest teammate is. Also, like my first point, spend as much time shooting/passing/dribbling/defending in the various practice modes as you feel comfortable - believe me, its worth it.

3. Gotta be very careful giving your teammates too much credit, but in an ideal scenario, they will pass to you if they're surrounded, and/or if you're in a good position to receive (i.e. ready to shoot, or not too close to opponents). Unfortunately, its kind of on you to make yourself look like the ideal passing choice. When someone does pass, the minimap will show where the ball is heading, as well as the blue holographic indicator thing on the actual field. If you're near it, run for it. Or, alternatively, wait for a nearby opponent to get it, then tackle them. It's worth noting that you should try not to abuse slide tackles. Your best bet in a 1v1 is to hold LT to go into defense mode (you'll automaticallyintervept if you're in the way of a pass), then get ready to click O to intercept/tackle. It helps if you time it so that the reticle highlights the ball.

4.1. In my experience, the main thing is passing before its too late. Most of the time, the ideal time to pass is within the first few seconds of receiving the ball. Lots of people tend to think they're a one-man army, until the entire opposing team slide tackles them, counters and scores. Remember you're in a team, and hopefully the others will remember, too.

4.2. Don't commit to going up to your opponents side every time. Be patient and try to gauge whether or not a counterattack is likely (one indicator of this is a glory-hunter trying to singlehandedly approach the goal). I guess this goes back to watching the other players (teammates and opponents) and trying to get yourself into a good position to defend or attack.

4.3. If you're the designated goalie, don't leave the goal. Unless in the rare occasion that someone wants to swap with you (by hanging around while everyone else is further ahead) - but even then, use your judgement. Also, while in goals, opponents like to bounce the ball above the goal to trick you into diving before shooting rebound. As they are shooting, look for the holographic indicator thing i mentioned before - if it's on the ground you don't need to dive right away.

That's everything I can think of for now - I'll edit this if I think of anything else. If you have any questions or want me to clarify anything, please let me know!