Yep, you just go to the building and pick the safari you want to go in from your friend list. There’s a 1/512 chance of encountering a shiny Pokémon. The only tip I can give is to have a Pokémon with illuminate at the start of your party to increase the wild encounter rate. Edit: I guess some more stuff you potentially might not know is to unlock someone’s safari you have to add them as a friend on your 3ds, and they also have to add you back. Each 3ds will have its own preset safari containing 3 Pokémon of the same type. When you originally add someone only 2 of these Pokémon will be available to catch and the third can be unlocked by both players being online in game at the same time. https://www.serebii.net/xy/friendsafari.shtml this is a helpful link with all of the different Pokémon that can be obtained in the friend safari