What would a 8 year Olds do at this park for fun? What would you recommend for that age?

There is a whole lot

My daughter is a short 4 year old and can get in at least 13 different rides. I was just there twice today. An 8 year old would have much more to do. Have fun!

There are plenty different rides and games as well as an arcade

They have many kid-friendly rides in the "Snoopy Land" section. There are many more attractions like Wild Water Kingdom, some roller coasters if they are tall enough, and the food (Chickie and Pete's, generic park food, funnel cake, etc)

There is Planet Snoopy for younger/shorter guests.