I am the owner of the Safari Zone and have beaten the Elite 4 but when I look up how to place blocks people just say press A and it will bring up a list but it doesn't, please help!
To place blocks, go to an open area and press A. Try it a couple more times and make sure you're not pressing any other buttons too. If you still need more help, you can talk to the warden who's inside the safari zone, he talks to you about placing objects too.
Hope that might help!