The rewards are claimable at the end of each epoch. An epoch is expected to last around 5 minutes. Your rewards will be automatically compounded (all your rewards will be staked without having to do it manually). You can withdraw your rewards by unstaking a certain amount from the validator node.
Please remember there will be a delay when unstaking (approximately 2 weeks). The purpose of this delay is to allow the network sufficient time to determine confidently that the validator those tokens were delegated to hasn’t done anything malicious - no need to worry though, this is a totally normal procedure in DPoS networks.
Please note that to be eligible for staking rewards for a given epoch you will need to have staked before the epoch begins.