I called a couple of the patients that I saw while on family med to inform them that they had an STD and that they and their partners would need treatment. It wasn't really a big deal - my preceptor asked if I felt comfortable doing it before turning it over to me, and it ended up letting her attend to more pressing matters in clinic. Not really super-heavy stuff, though (like, for instance, telling a patient that he/she has a terminal illness or very serious or incurable disease).
My first year, I volunteered with a palliative care consult service, and sat in on family meetings where bad news was broken to families (typically by the surgeon or the attending IM doc, with a social worker there as a support and to field non-medical questions). Eventually I became comfortable enough with those types of situations to join in the ensuing discussion, although it was never my place to actually "break the bad news."
Now that I am a 3rd year, the situations are similar - I am not the bearer of bad news (this is still typically either the senior resident or the attending on the service), but I feel much more confident partipating in discussions about life support withdrawal, end-of-life care, hospice, pastoral care, patient and family fears and concerns about death and dying, dealing with very emotionally distraught people, etc. It's not dropping the actual bomb itself, so to speak, but I think this experience will prepare me to assume that role with relative comfort in the future.
If you are interested in gaining some experience with professionally and compassionately breaking bad news to your patients (a necessary ability for pretty much any type of doctor, with the exception of maybe a pathologist 🙂), it might be worth it to shadow the palliative care service at your local hospital or volunteer at a hospice, where you can participate in family meetings and talk to dying patients about their experiences. Another option would be to spend some time in the ICU, where there are family meetings and bad news being broken on a regular basis.
I think it's important to become familiar with this stuff early on. You are going to have very sick patients on your 3rd year rotations who will get sicker/code/die while they are under your team's care - oftentimes, you will know the patients and/or their families very well, because you (as the medical student) will be spending the most time collecting information for your H&P, being very thorough, just spending time talking to the family, etc. As you are typically their closest point-of-contact at the hospital, it's nice to be able to help them through the difficult times and decisions that they will have to face. Of course, you should always respect your boundaries as a student, but even as an MS3 you can be a whole lot more involved than just deferring to your attending or resident all the time.