I hope you are a micro-manager, because if you are dealing with very young 3 year olds, that is an essential skill. It's important to perfect your 'neutral' voice, too.
I'm firm, but not a micro-manager, and it's not so necessary with 4 year olds. But young 3's are a whole different animal. They are just starting out, so to speak, and need lots and lots of guidance.
I like this website:
https://teaching2and3yearolds.com/category/preschool/
Magnatiles are a hit in the 3's room. Of course, they are popular in all early childhood classrooms! Cars of all sizes, and dump trucks are extremely popular. So are those large toy animals.
you might also like this site:
https://handsonaswegrow.com/activities-by-age/
Good luck! I didn't do well in the young 3's room, but I'm fine in the older 3's/young 4's room. Go figure. Who would think 6 months could matter all that much!