The DAPP will automatically create the token and be ready for arbitrage on the decentralized exchange (on ETH or BSC chain)
You can get Flash Loan from AAVE, Multiplier-Finance, or from PancakeSwap/Uniswap (thanks to flash swap). This is done for you in the dapp, just select the loan amount.
Now you need pay the fees of the Loan to start arbitrage clicking the deposit Button and after that click the execute button. Enjoy your profit. That's all.