Hey there. I volunteered here for 3 years and have sampled many departments, now a med student at UCSF. Sorry you had to endure the gift shop. ED is honestly a massive disappointment. Expect a never-ending barrage of "hey volunteer, change the sheets." The ED has a lot of turnover... it's a toxic environment. Also the staffing is ridiculous, since some days you'll show up and there are 2, 3 or even 4 other volunteers packed into the ED with you. The ED is nothing special either, and does not have many exciting trauma cases. I imagine most of those go to Highland in Oakland, which I hear has an awesome (but selective) volunteer program
Go to Same-Day Surgery. The CNAs and RNAs there are way more chill and willing to talk. Close by is GI and ask if you can watch an endoscopy. Also make friends with the rads lab techs, they will let you watch CT scans and stuff. You also get to talk with way more patients in SDS. MDs seem resistant to shadowing in general, but don't be afraid to ask to watch them work, even if you get some rejections. Honestly if there were too many volunteers on my shift I was just a waste of space, so I'd actually go volunteer somewhere else in the hospital that day.
The worst part of Alta Bates is it is not a teaching hospital for med students, and it is very bureaucratic and averse to lawsuits, so they are very leery of volunteers doing just about anything besides changing sheets and discharging wheelchaired patients. You'll need to find doctors who aren't scared of the administration.
If you want even more patient contact and a lot of work, I recommend the Nursing Units. You get to answer patient room calls, act as liason between nurses and patients, and if you're lucky, talk to the hospitalist MDs. The downside is sometimes the nurses will not like you bossing them around constantly and it can get pretty hectic on the floor. But this is the best opportunity to talk with patients since they are recovering and are pretty bored.
If you want to get a lot of this experience, you need to be willing to talk with staff and constantly ask to be able to watch or do things. So many volunteers there are scared to do that and stick with the menial labor. YOU'RE THERE TO LEARN TOO!