By now, almost all public schools have gotten the first day of fall classes out of the way. Many, like ours, have been in session for almost two weeks now. New routines can be hard for some people, especially autistics. I think it's safe to say that most people in general struggle with back to school time, because of the complete turnaround of scheduling, and daily tasks.
One thing that I've noticed is most kids in general have a certain level of anxiety, and apprehension the first few weeks of school, even "typical" kids. Everything is new. New teachers, new classroom, new schedules. Not to mention that many have transitioned into totally different environments, like from grade school to middle school, or even middle school to high school. They wonder if their friends will be in their classes, how their new teachers will be, and how this year is going to go for them. Some have to learn how to switch classes for the first time, or use a locker. (Those locks are anxiety producing for some of us!)
If your child has had a less than stellar experience so far, or their attitude has been not great, then it may be overwhelm caused by the new routine. Keep the lines of communication open between you, and them by asking them how they like school so far in specific ways. Ask what their favorite part of the day was, and what was their lest favorite, Ask who their locker is by, and how they feel about their teacher. If they're really seeming to have a hard time it might not be a bad idea to let their teacher(s) know. That way the teacher can keep an eye out for things your child might need assistance with, or even just throw some encouraging smiles, and conversation their way to reassure the child that they're a positive influence for them. Some kids are too shy to reach out first.
If you have a child whose needs are exceptional you may want to write an introductory letter to their teachers like this. It is helpful for the teacher(s) to get to know some of the basic needs your child has, and how to meet them, beyond the IEP.