RE: traveling during pre-med and med school.
IWBB covered it pretty well, but the timing and amount of vacation time during med school is highly school dependent. But basically except for 4-10 weeks off between MS1 and MS2, you won’t get a significant amount of time off until your 4th year. (Significant means >1 week)
MS4 students have a good deal of control over their schedules since they can pick & choose what electives to take and how to schedule them…….but residency interviewing takes 2-3 months so many MS4s schedule only light or no rotations during that time. Still if you’re clever and lucky, you can get a couple of weeks between rotations after you finish interviews to travel.
Also the timing of the start of residency varies a great deal by program and specialty. D1 had to report to her residency program no later than June 8 this year. Because she graduated in early May, she was able to take a nice 2 week vacation before she had to move, but other students in her program reported straight after graduation, with no time off in-between.
Every residency program will give its residents vacation, but the timing and amount is highly variable. (Usually between 2 and 4 weeks annually, but no guarantees that you’ll get off any of those weeks off consecutively.)
As for international travel during residency–there are some programs that offer international electives. Not quite a vacation since you’ll be working during your time in another country, but you won’t be working 24/7 so you have time to see the sights.
As for hobbies--as IWBB said if it's important to you, you'll find the time. Both of my kidlets have managed to sustain a myriad of creative and outdoor hobbies during med school and residency.