Lucky Emblems in Kingdom hearts 3 are "objects" that resemble Mickey Mouse's well known face&ears symbol. There are a total of 90 and are needed to unlock the Secret Ending, we need all the 90 Emblems in Beginner mode, 60 in Standard and 30 in Proud Mode in order to unlock it.

There are 11 Emblems in San Fransokyo:

1- In Hiro's garage check the right wall for the first Emblem


2- From South District Night Save point, face yourself East and climb on the hat of the big "chef", from here you'll see some red bushes with the shape of the Emblem.


3-Back to the Save Point, climb on top of the first Skyscraper you se. From the roof look North and you'll see a big "M" and below that a blue sign with the Emblem on it.


4- Now climb on top of the building where the previous Emblem was and walk to the North side, turn left to see the Emblem on the statue's fan in front of you.


5- From the previous Emblem keep going North, go past the highway and climb on top of the first building with a cupola on top of it, the Emblem is on the right side of that cupola.


6- From the previous one climb on top of the Skyscraper with the blue lights to your right, the Emblem is on top of it.


7- Now climb on top of the huge flying fish on the eastern side of the map, the Emblem is on top of it.


8- Now to the north side of the map, there's a Skyscraper in the middle of the map, reach the north side of it, you'll find the Emblem reflected on the stairs.


9- From here go west to reach the train's tunnel, go all the way to the West exit and turn around to see the Emblem on the wall to your left.


10- From the previous one keep going West and jump down to the right of the railway, the Emblem is on the side of the yellow car.


11- Now reach the top of the Skyscraper to the east of where you are, the one you just pass through, the last Emblem is on the very top of the Skysrcaper.


For a detailed walkthrough check the video below.