You can get creative if you don't have a lot of time to get exposure.
There are medical missions abroad type stuff, usually a bit spendy.
If you have disabled/handicapped relatives you've helped care for, gone to their appts, stayed with in hospital, lived with, that won't susbtitute for being on the clinical side of shadowing a doc but shows you are familiar with illness. You can.title it "family caregiving" if that was the case, but still need to round that out with other stuff.
Elderly caregiving jobs on craigslist are very easy to find, suck, pay like crap usually, but you won't need credentials. Memory care. It's direct contact caring for often ill people so even if you're just wiping their butts or grocery shopping or bathing help, etc, it counts towards your app favorably. A doctor can't shy away from the old, decrepid, delirious, crotchedy, slow, frustrating, or body fluids and smells they may have clinging to them.
You should really shadow a doc though. It's hard if you feel you don't have an "in" so you can contact your school's med advisor, pre-med club, or even your PCP to see if they know a colleague that might. Contact local med school, even if far away they may have someone in your area that is like an asst prof.
If you want to cold-call/email someone, you can try psychiatrists, theu don't get much interest from students, they love to yak given how much they have to be quiet and listen, and you'll learn a lot that will make you seem psychologically/socioeconomically saavy. Plus it shows patience (you don't get a lot of immediate cure), listening skills, all can help. I'm not saying this should be the first thing you go for, but I know people aren't knocking down their door to shadow.
You could shadow an NP. I grew up in a crap town where that was the only provider for miles and miles. Didn't shadow them but imagine that would get some sort of clinical hours to my name.
Be sure you have written a personal statement and put together a resume and transcripts to give any doc or organizer something to justify why you're worth taking under the wing to help into medical career.
Hospital volunteering, I did, but was really ****ty because I wasn't paired with a doc, for HiPpa and ass-covering it was just making beds and directing people around the hospital, so very lame duties.
I just remember how hard it was to get an "in" without knowing the right people or having any special certs.
I took my own advice for a lot of the above and got in on the first try, but my app was great otherwise, and it was years ago, for whatever that's worth.