As a non-custodial stake service provider, we recommend you do your due diligence and select a trusted wallet. Cosmos eco-system has several options, we recommend you choose any one of the following two.

Keplr -Or- Cosmostation

Ok, so you've selected a wallet. It's time to generate a wallet address. You realize generating a wallet address involves secret seed phrases and private keys. Best practices to avoid a cyber attack such as man in the middle attack and preventing your seed phrase from being stolen is to use a hardware cold storage device. Hardware cold storage is not mandatory or required but it can provide an added layer of security.
We highly recommend you get familiar with any of the following options available, such as Trezor -OR- Ledger

Rewards are earned every few seconds and technically vary depending on the respective chain's block time. Each time a block is verified the validator node will remit a reward to your staked wallet address. It is important to note, rewards are never compounded in cosmos ecosystem. Typically you would need to claim rewards and re-delegate those rewards if you wish to compound. Don't forget each time you claim-reward, delegate, undelegate, or re-delegate you will incurr a small gas fee.

Undelegations are subject to an unbonding wait period. For example, if the chain unbonding period is 21 days, the token will be available for withdrawal 21 calendar days from the timestamp value of the undelegate transaction approval. The unbonding wait period rule is universal to tendermint protocol and is applicable to all validators.