The ADA rewards circle
Simple but pretty hard to illustrate.
EPOCH 250 You decide to delegate your wallet to NOOPS (thanks).
EPOCH 251 A snapshot of your stake is taken.
EPOCH 252 Your stake becomes active (snapshot during EPOCH 251).
EPOCH 253 Rewards are calculeted, your stake is still active.
EPOCH 254 Rewards are distributed, your stake is still active.
The first time, you will earn rewards after 16 to 20 days, depending of your delegation day. And of course your pool have to mint a block to be able to distribuate rewards.
Your ADA stay in your wallet
During the whole process your ADAs stay in your wallet. Only snapshots count for the calculation of your rewards. So you are free to move your ADAs between snapshots.