If using the BQ25120A as a standalone device, you should connect the ILIM/IPRETERM and ISET resistors to configure your current limit and fast charge parameter following the D/S recommendation.
If configuring the BQ25120A via I2C: you do not need to include the resistors. Instead you can connect IPRETERM, ILIM and ISET to ground on your schematic, this will power up your device to the default configuration. Communicating via I2C will override the resistors configuration.