I transitioned from dev into management about eight years ago and haven't looked back since.

- You have to really like working with people and I mean all kinds of people, not just those you identify with. You'll have to build strong relationships with people from a diverse range of backgrounds, personalities, experience levels and cultures. You'll discover unconscious biases you didn't even know you had and it will be your job to mitigate against them (they don't just go away).

- People are messy and you will be in a privileged position to see behind the mask. They will bring their problems to you and these won't always be directly work related. You'll be expected to help in some way, but most of the time you won't have a clue what you're supposed to do or say. Don't try to bullshit your way around them. Learn how to listen and develop good coaching skills. If the problem is more practical, make sure you have a solid relationship with HR and other managers. You might need their help to resolve the situation.

- Schedule regular one-to-ones with your direct reports and don't bump them ever. What this really means is when something comes up (vacation, sickness, conferences, workshops, etc) reschedule at the next earliest, convenient time or mutually agree to skip it. Send a clear signal that you value this time together and only exceptional circumstances will move it (being remote isn't exceptional). When it comes to the actual one-to-one, do some research on how to get the most out of them and adapt it to the individual. There's a ton of material out there.

- Not everyone is going to like you, get used to it. Sometimes it's a mismatch in personality types, sometimes it because of something you did and sometimes it's just because you're a manager and you represent the company; the reasons are infinite. Most humans crave acceptance and have a deep need to be liked. You have to learn how to dampen this instinct and intuit other ways of evaluating your performance. I'm not saying being a jerk is ok, but learning how to be resilient is important.

- Never stop learning. When you're a developer there's always a new language, or paradigm or technique; the field is constantly evolving and management is no different. It's every bit as much of a craft as programming. Read books, listen to podcasts, go to conferences, learn, learn, learn. You'll start off being Unconsciously Incompetent and will need to progress into fluency and mastery. If you only do on-the-job learning your development will be slow and there'll be a cap on your experience. You'll no doubt receive a ton of recommendation in this thread, but I'll link to a couple meta-resources I've found useful [1][2]

- Management and leadership are two very different things. You can be great at one, but suck at the other. When I first moved from being a developer to a manager I focused all my energy on the management side of things (coordinating work, removing obstacles, administration, hiring and firing... getting shit done). I was a great manager, but a lousy leader. People want to work for someone who's competent, of course, but they also want someone who inspires them, who challenges them, and who understands their needs. Learn what it means to be great at both and focus your development accordingly.

- If you're managing developers, or people in any technical field, you may need to be able to have conversations about their work. Opinions are massively divided about this, but I personally believe staying on top of industry trends, and maintaining a technical mindset, is important to maintaining credibility and empathy with your direct reports. Let's be honest though, if you stay as a manager you will probably never be at their level again, and as the years roll by you will become increasingly incapable of doing their job. This freaks a lot of new managers out and I've seen them either try to hold on to their former status (and fail) or they abandon management after a few years.

- Impostor syndrome is real. You will probably get it. A lot.

[1] Podcast (personal favorite) - Coaching for Leaders: https://coachingforleaders.com/

[2] Podcast - Manager Tools: https://www.manager-tools.com/podcasts