I'm almost 8 years old as a developer, start as QA, then went to frontend, backend, and then switch again to frontend, where I did my time focus in UX/UI. Currently, I found myself working as a frontend engineer.
Learn to listen
During my career as a dev, the one thing it was hard to take at the beginning was the feedback. Over the time I work after-hours to try to improve my skills, some of the meetings end up in '... I like this, this and this, but could we improve on this or that ...', so don't take personally the things and work over that.
Do one time at the time
In my case multi-tasking never work, I became obsessed with the use of the board of Jira, I need to get everything in order there, what task was in progress, what needs to be done next, and what was the priority of the tasks so at the end of the day I wasn't too disperse in my head worrying about other tasks.
Learn the basics
At the time I was trying to keep up with the trends, over time this become difficult, probably every day a new JS library pops out. At the same time that a new library comes I notice that it was really familiar to other libraries and if I get the principal concepts of the library/fw I will be able to make the code work. Go to the basics, learn JS, understand the differences between them, the holy bible is You don't know JS.
Don't overestimate soft skills
Most of the devs/Engineers are really good in what they do, but they lack soft skills, be always conscious about that, remember that your career also includes building a reputation, if you had the reputation to be a hard people to work is going to be hard for you move in your company.
Look for something else
Once you learn the basics I'll hardly recommend learning about performance and lastly about design, as devs we are always in the mindset of a developer, like, There should be a link here, and when the user clicks the routing should render the page; but we almost never put in the user seat, try to use your system/app with the mind in blank, like you don't know what happens if you click there, remember this "If the user doesn't understand your system is going to be afraid to use it".
This is everything, for now, let me know what you think and if there is other advice that you should consider for the new ones.