By setting personal boundaries early on, you can help design a life that has free time for you to enjoy your hobbies, spend time with your friends, exercise, read - whatever you like! If a job is drastically inhibiting on your ability to live a 'full' life, it may be an opportunity to reflect on if that job is serving you.
My job does bring me joy and purpose! I feel lucky that I have found a career that allows me this. Though, be warned, it may take TIME (2, 5, 10, 20 years!) to get to a place where you feel a strong sense of purpose. And even then, your understanding of 'purpose' may change - maybe having a family or volunteering or your pet brings you purpose and your job is your job. No one can tell you what is the 'right' way to live your life.
I'm a paramedic in Washington State. I can't deny that this job makes me stress a whole lot. We deal a lot with under served communities and life or death situations. We see the real parts of the city that a lot of people don't get to see. I could have up to 9 very sick patients on one shift if it's just a Tuesday, but I can say that this is the only job that has challenged me in the most visceral and mentally exhaustive ways. It's the job that has given me purpose in life. Enough purpose to pursue a career in medicine and get my license as a doctor. Between the people that I work with and that I help, it is all worth it.
As far as my free time goes, I have plenty. I only really worked 3 days a week at most, which can be less than most careers do. The hours are long, but really when anyone gets home from work I don't think anyone has the energy to do much, so really time used is all the same. I like to do a lot of things from video games to hanging out with friends. It's a balancing act for sure, but it does need to be fine tuned for a while before you get it right.
Hope this helps!