I am a sub in a 5th grade class today and I don’t understand these kids

I am a sub in a 5th grade class today. Normally this school has 300 kids per grade but now they have 600 per grade. This is the first time I worked a job subbing for this school and I don’t know their system besides the sub training. The teacher left me a lot of notes about how to handle situations. <br><br>Things that make me confused:<br><br>1. One of the students got in trouble for not following instructions and she started crying. I didn’t know how to comfort her and this school has so many teachers I don’t know who to go to. This school has a mental health worker, but I didn’t know how to reach them. I tried to talk to the nurse, but she said she’s busy with the children sick with covid. <br><br>2. The students left for recess and I didn’t know they were supposed to have a sub with them. This other teacher happens to be there and saw me without a teacher with me. She started lecturing me and telling how I could have gotten in a lot of trouble if a kid got hurt and I didn’t know what's going on. This school has so many teachers I don’t know who to go to for help. <br><br>3. Some of the students were asking me about certain cards and it was for some system they use for rewards called "gotcha cards". I didn't know what they were but memorized what they look like to help deal with the kids. <br><br>4. Some of the students got a note for their behavior for putting their name on the "stoplight" board. I didn't know what that was, but memorized what it looks like to help deal with the kids. <br><br>5. This school has so many teachers and I wish they put some kind of identification so I know who everyone is. This one teacher was helping me with a issue and I don't know what her name is. <br><br>6. The kids kept on losing their work and I don't know what to do. I just gave them a new copy. <br><br>7. There was a kid that had trouble with their technology and I didn't know how to help her. Another teacher happened to be in the classroom and helped this kid. <br><br>8. The kids were asking me if they could have snack time, but I didn't know how to help them. I didn't see any snacks around to help them. This one teacher happened to walk into the classroom and there were some snacks in their desk that this teacher gave to the kids. <br><br>9. I didn't know how to operate the copier to get the copies ready for them. I had to get help from other teachers because I have never used that copier before and I didn't know how to get the copies. This one teacher was a little mean telling me how it's been there for years and I should already know how to use it. I didn't use that copier before how am I supposed to know?