Instructions
Travel to the Safari Zone, marked on your in-game map, once Baoba calls you. Upon arrival, he will ask you to capture a Geodude inside the Safari Zone.
Enter the Safari Zone and keep walking until you find a Rocky Zone. The zones that appear here are random, so you may need to walk for awhile or reenter the Safari Zone.
Select either "Mud" or "Bait" to entice the Geodude. Throwing mud at it makes it easier to catch, but more likely to run away, and bait makes it stay, but then it's more difficult to catch. Throw your Safari Ball whenever you're ready to catch it. If it stays, exit the Safari Zone.
Press "X" and select "Pkmn." Select your Geodude and move him to the top of the lineup, and then return to the game. Press "A" next to Baoba to speak with him, and he will congratulate you.
Wait 17 to 24 hours, and Baoba will call you in-game, asking you to return to the Safari Zone. Upon arrival, he will give you a random block to arrange in the Safari Zone, and then challenge you to find a Sandshrew in the Zone.
Capture a Sandshrew the same way as Geodude, and return to Baoba to show him. He will congratulate you and send you off.
Continue waiting in 17 to 24 hour intervals. After enough time has passed, Baoba will keep calling you to tell you that more blocks are available.