A good heuristic in life, when in doubt of what's important, is to do the stuff that gives you energy, makes you feel more alive.
Examples:
Surround yourself with people that inspire you, not people that put you down, make you feel small, or that only complain
Do stuff you like, because that gives you more energy, and makes you enter the feedback loop of energy, interest, skill and focus: interest makes you more focused on something, which makes you better at it, which makes you even more interested in it, and energized, etc.
Focus on building skills, not specific careers, which can be framed as: use energy to generate even more later. Careers rely on specific circumstances which can always change, but skills stay with you and create more energy (see also point 2.)
Work-life balance can be framed as: don't let the stuff that drains your energy bleed into what you enjoy. This doesn't apply if you genuinely enjoy your work, though of course you still need some rest from time to time
Do not repress stuff, such as emotions, ambitions, important conversations, because it takes energy to repress those things, and they will continue to exist regardless: problems don't magically disappear by burying your head in the sand, stuck emotions will create problems in your life, etc.
Change your environment to get stuff done, because it only requires you to use energy once to make a more lasting change, without the need of willpower or favorable circumstances
Of course as any advice or heuristic in life, it has its limits.
For one, some people might genuinely feel energized from hurting other people, or the sense of feeling superior to others. Even in those cases, it might be worth examining the underlying dynamic behind the energy, as it is rarely a specific activity that we find energizing, but more like the interaction between 1) what it provides 2) what you're good at 3) what you care about.
For instance, I used to be very energized by video games, because they game me a) a sense of freedom that school didn't b) a sense of agency through getting better something, which again school didn't c) some form of connection with other people, with online games. Those things stopped being true over time, and as a result, I now feel like video games are a drag more than anything, and look for activities that hit the same core needs without the rather addictive nature of games.
Another limit of “do what energizes you” is that a lot of people who desperately need rest will interpret this as encouraging even more activity. I have found that closing my eyes and doing nothing—not even meditation per se, which to me involves some type of focus—is one of the most energizing things in my day, far better than taking a nap for instance.
Energy is tricky because in other circumstances, what you need is not static rest, but a specific type of action to address an emotional knot,2 which is a problem that needs to be released by untying an underlying problem. For instance, being tired by your inability to progress on a project you really want to complete.
But I think broadly speaking, what I observe around me are people who need way more conscious rest, and it is also worth noting that even the problems that require some type of action, such as emotional knots, are greatly helped by having a consistent amount of do-nothing time each day, to reflect on what you need the most, and to not waste you energy in hundreds of different directions.