What are the best things a sub can do?

 I started working as a substitute teacher in a middle school a couple months ago, and so far things have been relatively okay. However, I am treated mildly like a neausance by other staff at times and I’m wondering if perhaps I’m falling short somewhere in my responsibilities as a sub and if that’s the cause. 

  A day with me as a sub usually consists of:

.I look at the sub plans, if I can’t find any I call the office and inquire and they usually hook me up with another teacher to give me some sort of plan.

.I introduce myself to the kids (which I’m having to do less anyways because I’m there every school day.)

.I tell the kids what they’re doing, what they need, etc.

.I offer to help where I can (however sometimes it’s difficult because a lot is different since I went to middle school, like how they do math specifically.)

.I let students leave the room one at a time which is the school rule.

.I write notes on both good and bad behavior (I don’t know if maybe this makes my notes too long but I do try to keep it brief.)

.I try to clean the room up a bit before I leave however I may fall short here as sometimes it’s too much and I run out of time before I have to clock out.

That pretty much summarizes my class periods, sometimes I have to be harsher with the kids and sometimes I can be more relaxed; it really depends on the day.

Is there more I can do or maybe should be doing? My district doesn’t provide training so I kind of just got thrown in and took advice from my husband who is also a sub. I want to build good relationships with teachers but sometimes it just doesn’t go well at all right off the bat. I’m autistic and not the best at making small conversation but I do my best to have a cheery tone when I do talk. I’m not sure if I have like an off putting demeanor but going in to the job I didn’t know I had to worry about that in a professional setting.

Some of the teachers get along really well with me but I’m still not sure what I’m doing wrong for the others.

Any advice is greatly appreciated. I’m just really tired of feeling super unwelcome when I’m doing something as simple as going to the lounge to use the bathroom or even using the elevator to move from classes to get there on time. (Because it’s kind of impossible to move efficiently through a hoard of middle schoolers.)

I don’t want to get into specifics but regarding teachers and the “mild neusance” treatment I’ve been yelled at, been mistaken as a student and they continued to be rude about it after I made it clear no harm was done, and have been told I need to “do my job.”

I should probably also include that I avoid touching my phone except to check the time because this school has no bells so I have to keep accurate check on it. I’ll pull out my sketchbook or journal to pass time.Or on rare occasion if the class is really well behaved and on task I’ll loosely read (however I don’t do this one often.)