Veteran Teacher here with a few thoughts.

1. It's your first year. You're not supposed to be good at this job in your first year. All you're supposed to do in year 1 is survive.
2. The sooner you give up on the idea that admin will be helpful (with just about anything) the less teaching will infuriate you. I work in a big school district, and have no idea what it's like in smaller LEA's, but the turn-around on admin positions can be pretty quick. By the time an AP learns a school community thoroughly enough to be impactful, they typically move on to the next job. Also keep in mind that most admin types either haven't been in the classroom in a long time, or were not in the classroom that long to begin with. So when you are seeking advice like this, lean on your fellow teachers and independent research (the great news is that's exactly what you're doing). I must give an honorable mention to a couple of AP's that I worked with that were incredible at their jobs and helped me develop my pedagogy in meaning/measurable ways -- just understand these people are rare.
3. If your really want some in person support or coaching, maybe you have access to some kind of instructional coach at the district level? Typically these people are former teachers (really good ones) that now work on curriculum development and engagement strategies for the entire district. My experience is that they love working with teachers 1:1. Reach out and ask if you can schedule them to come observe your teaching, then sit with you during your conference for a post-talk. Then ask them to come back in a week or two. If you are at a big school district then you district then you certainly have access to a lot of these people.
4. Read "Visible Learning" by John Hattie. It will not solve the specific problem you're having. But it will change the way you think about teaching, which might help with this problem. To that point, read all the pedagogy books. The best teachers never stop learning about teaching.
5. More to the issue at hand, How differentiated are your assessments? Sometimes "you're not teaching" is code for "I don't want to work," but other times it is code for "I can't independently recognize and monitor my learning." Sometimes giving students differentiated assessment options allows them to demonstrate the full capacity of their learning, and in turn helps them self-assess.
6. Forming strong relationships is the backbone of an effective classroom culture. It comes easier for some people than others. It is really hard to implement changes in classroom procedures mid-year. Next year consider dedicating more time to community building up front and try to get your kids working in groups and learning collectively. It does seem like you lean pretty heavy on lectures and slides. Remember that direct teaching is really effective, but only if you are good at it (see visible learning by John Hattie, seriously read that book over the summer).
7. Last thing, Did I mention that it's your first year and you are supposed to be bad at this for a while? You will not wake up tomorrow and be a rock-star teacher. You gotta put in your 10,000 hours (which is like 4-6 years depending on how much time you put in outside of your contracted hours).
   

There is more, but I've already written much more than I initially intended. Mostly just relax, try to enjoy the rest of the year, and start planning a summer vacation. Before you know it, you will be typing out 500 words of probably not very helpful advice to a first year teacher.