To get some testnet tokens use Standard Protocol Discord faucet available under this link: https://discord.gg/TdWwNR7N . You can get Your OPT tokens by entering this command !drip <Your Opportunity Testnet address>. You will get 50 OPT tokens per one command. You can enter this command every 1 hour getting 50 OPT.
The tokens should be visible in Your account almost immediately.
Now transfer some of You OPT tokens to the controller account. This is in order to have enough liquid funds for paying transaction fees when bonding and unbonding funds.
To do so click the send button indicated by the arrow.
Then choose Your stash account from which You are making a transfer and controller account to which You are making the transfer.
Input the amount of tokens You want to transfer and click Make transfer button.
In the next step if everything is correct click the Sign and Submit button.
Now polkadot.js extension will pop up. In this window provide Your password to stash account and click Sign the transaction button.
Controller account should now hold the transferred amount of OPT tokens.