Autism testing

Jami Lynn💜momma of five

My 8 year old step son is being tested for autism and dyslexia tomorrow afternoon. I don’t really know what to expect because I’ve never had to deal with this before. The testing is for three hours and I also have to take along my other kids. I’m kinda stressed about it (mainly occupying the others) while he’s getting tested. What can I expect for the testing and how long does it typically take to get results back? I’m sure every place is different but I’m trying to get an idea