To send ada, you need the recipient’s Cardano address. Add the address and the amount you want to transfer to the recipient in the ‘Send’ tab of your wallet.
To receive ada, copy your ‘Receive address’ to the clipboard from the ‘Receive’ tab. Next, share it with the person who is going to send you ada (or other Cardano native assets) or use it yourself to send ada from another wallet or exchange.