You might also ask on your neighborhood Facebook group or listserv about school Facebook groups you could join. Our PTA used to organize a back-to-school popsicle social at the public park near the school, usually the weekend before school started.
Most schools post class lists at the school on the Friday (typically) before school starts, which is also a good way to at least see the school, even if you can’t do a full tour. Ask when you register, or check the website in August for information.
Some schools also send a postcard the week before that lists your child’s teacher, but I’d still go to the school on the day the lists are posted. Ours always had tables set up with information about aftercare, signing up for the PTA, etc. And you and your child might get lucky and have a chance to introduce yourselves to another family in your class if you’re finding names on the list at the same time. My kid always wanted to see who would be in her class, even though she knew who her teacher would be.