I'd deal with the not knowing anyone at the school part so that you can also give him some more independence. Invite a kid from school over to play some afternoon. It's certainly scary when you don't know anyone, but the easy fix for that is to have some familiar faces.
My elementary aged kids were all desperately shy (really, I mean desperately) in kindergarten, so I certainly understand about that. But I did want to convey to them that I had total confidence they could handle things and be fine. It certainly won't kill a kid to be walked to the classroom door, but it's empowering for them to do it themselves (and for them to see that you think they can do it).
I wonder if it really matters much to your son whether he's dropped off at the door to the school or the door to the classroom? Has he said so? Even a shy kid can walk down a hallway, and he'll be doing it for the rest of the day without you. Is it possible it just makes you feel better to walk him, especially if he's visibly upset? It's a big transition for the parents from preschool, where parents usually are free to go in the classroom, to "big kid" kindergarten, where one of the primary things kids are learning is age-appropriate independence -- from opening their own lunch containers and putting on their own snowsuits, to walking down the hall to their classroom. I know with my first child I'd drop her off and then sneak around and peek through the window to make sure she got to her classroom, lol. But it was my issue, not hers. You know your son and when he's ready, and if he's really not ready by all means tell that to the teacher, but make sure as soon as he is ready (which might be before he thinks he is) you give him the favor of that kind of independence.
[And I admit this is all rather hypocritical of me, because my fourth grader has been walking my kindergartener to her classroom for the first three weeks of school. It's the fourth grader who's really into it, lol. But I do make a point of letting them both know that it's fine to walk together if they want, but that the younger one is totally capable of doing it by herself.]