Quick start with Firehose for Cosmos can be found in the official Firehose docs. Here some quick links to it:
fireinjective fetch {FIRST_STREAMABLE_BLOCK} --endpoints {VARA_RPC_ENDPOINT} --state-dir {STATE_DIR}
firemantra fetch {FIRST_STREAMABLE_BLOCK} --endpoints {VARA_RPC_ENDPOINT} --state-dir {STATE_DIR}
fireinjective fetch {FIRST_STREAMABLE_BLOCK} --endpoints {VARA_RPC_ENDPOINT} --state-dir {STATE_DIR}