Download and install Metamask from the following link: https://metamask.io/
Buy or send BNB to your wallet, you can buy it directly from Metamask or from one of a known CEX
Go to https://pancakeswap.finance/ and connect your wallet, then add the $CLEO token using this contract address: 0x8087fdC95e14E7DBF0DE5A08b2558e54793795C0
After adding the contract, you should be able to swap BNB for $CLEO. Give some time for the transaction to be confirmed.