Summarize this article in one sentence.
Some things, such as world events and natural disasters, are beyond your control, and there’s no use beating yourself up about something you can’t change. Focus instead on things you can change, like your own choices and judgments. Think of a tennis game. You can’t control things like the skill of your opponent, the referee’s calls, or how random wind gusts might affect the ball. On the other hand, you can decide how much to practice before the game, to show up well-rested, and not to stay up all night partying before the match. Work on having more self-control and self-awareness. Being stoic doesn’t have anything to do with just not talking. It’s more important to think before you speak, whether you’re interested in philosophical Stoicism or want to be stoic in the dictionary sense.  For example, if someone insults you, don’t just blurt out an angry insult back at them. Don’t engage them in an emotional fight, but consider if there’s any truth to their statement and reflect on how you could better yourself. If you feel yourself getting upset and can’t focus on the situation’s facts, try to visualize pleasant surroundings, sing a song in your head, or say a stoic mantra to yourself, such as, “If it’s not in my control, it’s none of my concern.” There’s nothing wrong with talking to people, but try not to ramble nervously and meaninglessly. You can’t control other people, so there’s no reason to be nervous. You also shouldn't feel like you have to conform to other people's standards, especially if it means compromising your own morals. Try to learn at every opportunity, but don’t be a know it all. You can’t learn if you already think you know everything. Wisdom is a core Stoic virtue, and part of cultivating wisdom is admitting that you have a lot to learn.  Educate yourself whenever you can by reading books, listening to podcasts, watching documentaries, and (obviously!) reading how-to guides.  You could listen to podcasts like TEDTalks, RadioLab, and StarTalk Radio. Browse Netflix and other services for documentaries on subjects like nature, technology, and art. If you want to read more about Stoic philosophy, the contemporary philosopher William B. Irvine is a leading voice. His writing is accessible and doesn't use lots of unapproachable philosophical jargon. A true stoic isn’t interested in emotional conflicts, retribution, revenge, or holding grudges. But that doesn’t mean you have to be a cold, distant, isolated grouch. If someone wrongs you, you can still have sympathy for them even if you don’t engage them in an emotional conflict.  For example, if someone you care about lashes out at you, don’t just give them the cold shoulder. You could say, “I don’t think it’s wise to just toss insults back and forth. Let’s take some time to cool down so we can deal with this situation rationally.” "Don’t get mad, get even," is not at all stoic, so never try to get revenge. If you’re a manager in charge of reprimanding an employee, think of a fair way to hold them accountable instead of blindly punishing them.

Summary:
Accept what you cannot change. Think before you speak and emotionally react. Don't worry about other people. Stay humble and open to new knowledge. Focus on being fair instead of being harsh.