A simple check I use: if I imagine myself a year from now, will I wish I had stopped doing this sooner? If the answer shows up immediately, that’s a sign.
Maybe it is a side project you have been dragging around, or a job you already know you’re done with. Sometimes it’s a habit that drains you more than it gives back, or people you keep saying yes to out of routine instead of choice.
Your time is the one thing you can’t get back. Do not put it into something you know would go nowhere, or into something that is draining you for no reason. It is ok to drop commitments that do not fit who you are trying to become.
Put that energy into what will still matter (to you) a year from now - the work you actually care about, the skills you want to have, and the people you want to keep close.
In the end, it’s all about minimizing regrets.