Research

Research is not necessary; however, it would be good to get involved in at least some research just for the sake of checking whether it's right for you. Research and medicine are, after all, very much intertwined.

You don't have to do research if you know it's something that you're not interested in. (I.e if the particular lab/subject matter doesn't interest you). It won't hurt your chances if you have other substantial experiences to back up your application. I have absolutely zero research and did just fine this cycle. I do, however, plan to do research later on during med school.

If you want to apply to schools that highly value research, then do research. If you have other accomplishment in the world of volunteering and whatnot, then don't. From what I remember, it's a positive thing that beefs up your resume, so if you are even remotely interested, look around for an opportunity and do it.

While research is not necessary for getting into medical school, it is pretty much expected if you are aiming for the research-oriented medical schools (usually the ones in the "high ranks" according to US News).

The necessity of research experience is highly dependent on what type of schools you want to attend, as Concordia alluded to. If you are thinking you would like to attend one of the top 20 schools, research becomes rather useful in your application. Those schools are ranked where they are because they bring in a lot of research money, and thus perform a great deal of research. That's not to say that you cannot get into one of those schools without research experience, it just makes it a little more challenging, and you will need other strong activities in your application.

Regardless of whether or not it is important for the particular school you hope to apply to, I would recommend attempting to get involved with some research if at all possible. You may find that you really enjoy it, and it may influence what type of medicine you want to practice (academic vs private, for instance). Best of luck.