Delegation in Cardano do not require from you to send the coins (ADA) anywhere. You can delegate through official wallets like Daedalus and Yoroi (browser applet). Those wallets provide you a list of active staking pools, you just pick one and click "delegate". This is something like a "promise" of supporting particular pool, not an actual transfer. So you can use your coins any moment you want. Don't ever fall for scams asking you to send any transaction with ADA!