I've been playing Overwatch, a team-based (6 vs 6) first person shooter game. This raises a variety of interesting problems.
There are 23 heroes. To learn best, do you specialize in one or two heroes? Or do you play a wide variety and try to pick whatever is the optimal hero at any time? (You can switch heroes mid game to handle different situations. Hero switching is part of the game.)
Do you practice by playing the game, or do you do something else to practice like target practice shooting or 1v1ing a friend? Do you play more or do you read guides and watch gameplay footage from top players or tournaments? Do you spend time on test experiments to learn details about the game physics?
Do you do your best to try to win every game, or do you sometimes do something for learning purposes which you think can help you win future games?
How much attention do you spend on your mouse settings, your mouse pad, your hardware and frame rate, etc? Or just don't worry about it and play a lot?
Voice chat is integrated into the game and very important for coordinating better teamwork. How do you deal with mean people who insult you? People on your team who get angry and try to lose on purpose for revenge? People who are passive, quiet, and non-communicative? People who don't listen and don't follow team strategies? People who disagree about strategy?
Some of my answers:
Don't get into arguments with your team. Ignore assholes and mute them if they're persistent. (Sometimes I ask people to stop flaming and just focus on playing the game. Sometimes this works but sometimes they just keep at it and respond to the request with more flaming. If I ask someone to stop and they continue then I definitely mute them.) And if you really want to win, it's better not to trigger these people since they're really common. If I play Ana (healer) then basically no one gets mad at me ever, but if I play Widowmaker (sniper) then I get complaints in the majority of games (often there are complaints in the setup phase before the game even starts, so it's not even based on my quality of play). So it's easier to win games with Ana just because my team is happier.
Focus on one hero at a time until you're comfortable with them. It's really hard to learn much if you play a hero for one or two games then switch. It really helps to play at least 100 games in a row with one hero (play them at least 90% of the time, you can't realistically use them 100%), and more is better. (Games take like 10-15 minutes typically.) Once you get a good handle on one hero, then you can learn a second hero. Then a third. And keep going back to the heroes you're good with regularly to stay fresh with them. You learn more by understanding several heroes to see the game from multiple perspectives, but focused practice on one hero at a time is really valuable to learn them initially. Playing all the heroes is a bad idea which will spread you too thin, but playing several is a good goal to work towards. (It's a good idea try all the heroes a little bit at first to see which you want to learn and to learn the very basics of what they do.)
Don't just play the game. Watch a few tournaments to see what good, organized teams do. That's worth being familiar with to get a better idea of optimal play. Watch some pro streams who play heroes you play to see gameplay from the perspective of one really good individual. Try to find streamers who explain what they are doing and talk a lot so you can learn more. Make sure the streamer is a very good and serious player, not a casual "fun" streamer, but it's fine if they are like #1000 in the world, not #5, that's plenty good enough. Read and watch some guides until they get repetitive. Each different information source offers some value and you should try them all, each has its own strengths.
Playing to learn is good (like playing a hero you're less good at but want to practice). But try your best to win sometimes too. Do both. I bought a second account so I can practice on one and try my best on the other.
Playing a lot is important but it's also good to practice specific stuff like aim and 1v1s at least a little bit. It's another information source with its own strengths, so try it a bit. I do recommend focusing on playing the most, but try everything else a bit and see what value it offers.
Focusing on playing and not setup is important, especially when you're new. But mouse settings are legitimately a big deal. Many new players have their mouse move way too fast. Not like 20% too fast. Like 10 times too fast or more. I started out that way because it works fine in other types of games and for regular computer use. I lowered my mouse speed many times. Over time I improved other aspects of my setup, but the rest weren't urgent and could be done gradually so it's never very much of the time spent on Overwatch. (Like play for 20 hours, than spend half an hour improving your setup. Repeat. That's a reasonable ratio. It's worth optimizing stuff if you play a lot, but you don't want to get distracted from actually playing.)
Play the heroes you want to play as long as they are reasonably good. Which heroes are really good changes over time as the game gets new patches. Don't chase what's currently considered the very best heroes. As long as your hero choices that you like are pretty good, just stick with them. And don't play a hero you're bad at just because it's the right hero pick in the situation. You can do that to practice, but don't do it to win. A lot of players pick heroes they suck at in an attempt to win the game because they think the hero is needed in the situation. But having that player on a hero they are good at is way more important than having the optimal heroes.
If people don't communicate and don't do teamwork, you have to try to work with them. Watch what they do and help them with it. It's better that the whole team follows him and does an inferior plan than he just does something alone and dies. It's possible to win if you work together even if it's not the strategy you would choose. But if people are doing different things separately against a full enemy team, you'll basically never win. It's very hard to win any fights against a full team of 6 players without also having your own 6 players all fighting. So if someone attacks at the wrong time, go attack with him too. If you die, so what, you'll just respawn at the same time as him, so it doesn't really matter. (What else are you going to do, stay alive and wait for him to respawn? That will take the same amount of time. You might as well go try since everyone has equal respawn times, there's often no harm in dying at the same time your ally dies. If you lose a fight you lose the fight, it doesn't matter that much if you wait for one guy to respawn or everyone.)