Change Active school

[MercuryTune]

Hello. Mine sims living in Island Paradise town. There is school but with stadium, and when mine child sims got opportunity to receive scout reward he couldn't do that. There is another school in library but that building looks not really beautiful. So I downloaded building named "school" but it not work. Who knows how to do active school?

[Steellace]

I'm not sure that I understand what's going on in your game.  I haven't downloaded a school lot from anywhere, but I've added one a couple of times.

For a school lot, you need a community lot tagged "Visitors Allowed."  Then edit the empty lot (with the build/buy button).  On the far right of the build tab, you'll find an icon named Community Objects.  You will find school buildings mixed in with all the other types of buildings.  Pick one, put it on your lot, and decorate around it as you desire.

If you have replaced your school entirely, the game will start sending kids to the new school.  If you have added a school lot, it takes a little time for kids to start going there.  I found a mod that allows me to "force" them to the new school, but it will eventually happen on its own, sending the kids to the school closest to their home, I believe.  I hope this helps.

[Trip]

It's probably because the School/Stadium rabbithole in Isla Paradiso is a combined rabbithole (combines two different ones into one building), and combined rabbitholes almost never play well with opportunities.

I don't know how to make the second school you placed the active one. Sorry.