It soooo depends on the OB. It really does. I know they are villianized a lot her on MDC but it doesn't mean they are all bad. You can find some really caring ones who might offer interventions but don't care if you object and will follow your wishes. They are not all evil and I don't think it's a good idea to go in expecting to not like the OB, kwim? Also if you don't click with this one then call around and set up some interviews.
As for "interventions" for the first appt...I had an OB with my first, I wasn't high risk or anything but I can tell you what they did: I was weighed, peed in a cup, got blood drawn for the first appt, did have a pelvic exam although I hadn't had one in a long while so it was needed, and they used the doppler to try and find the heartbeat. Other than that, my OB just asked if I had any questions, and went over some really basic pregnancy stuff with me. Oh and I was unsure about dates so I had a dating u/s.