To add liquidity to an AMM like SUSHI you will need 2 assets in a 50/50 split in terms of dollar value and some ETH for gas fees.
SUSHI have created some documentation here to guide you through the steps: https://help.sushidocs.com/guides/how-to-add-tokens-to-sushiswap-exchange-as-an-lp
Once you have added liquidity to Sushi you are ready to Stake on Bao.finance