I think SG could be "shield ground".
For USB 2.0 device to work with USB Type C, you just need to connect the usual 4 pins (VCC, GND, D+, D-) and additionally connect CC1 and CC2 to ground each via its own 5.1k resistor (to set the correct USB device mode). You can ignore all the other pins.
Just watch out - because USB-C is reversible, all pins exist in pairs: 1 in the top row and one in the bottom row. So D+ is actually 2 pins - DP1 and DP2, that need to be connected together. Same with D- (DN1, DN2) VCC and GND (there are actually 4 pins for each).
Hope that helps