I barely remember July of my intern year, but having worked with brand-new interns in the last 3 years first as seniors then now as a new attending, I'll tell you that for the first 3 months or so (until ~Labor Day) there's very little expected from interns. In the beginning the interns are literally just trying to keep their head above water and learning their way around the hospital (figuring out what to avoid from the cafeteria 😉).
The only thing that I really expect interns to do is to NOT do anything that can jeopardize a patient's safety. Although this sounds a bit daunting, there has only been two interns who I worked with where I actually needed to explicitly tell them that what they are doing is dangerous. You actually know more think (but, yes, at the same time, think you know more than you know 😉) Clinical medicine is highly, highly repetitive, and soon you will organize your thinking into "illness scripts" for the common conditions -- as time goes on these management algorithms get more and more refined, and you'll see that the vast majority of medicine patients are all just different flavors of the same 10-20 common illness pathways.
I tell everyone at the first week of July to ask lots of questions. If you don't know something and you feel odd about it, ASK someone (see above). We've all been there. Read while you can, but I don't think it's imperative to really do that much especially in the first half of intern year. Focus on getting out on time, getting enough sleep, exercising, and eating well first. You'll learn the medicine through seeing patients.
Once you've had about 2 blocks of inpatient floors, clinic, and ICU each you should be much more comfortable. By around Feb-March of intern year I was barely running my plans by the senior before presenting to the attending (they won't care anyways by that time as long as you do a good job 😛).