How to stake Aptos?

I'm a bit puzzled about staking Aptos. Could you please explain how it works? I've heard that staking is a way to earn rewards by locking up my tokens, but I'm not quite sure about the details. Is it necessary to have a certain amount of Aptos tokens before I can start staking? And where can I do it? Is there a specific platform or wallet that supports staking Aptos? Also, how long do I need to keep my tokens staked to earn rewards? Are there any risks involved in staking Aptos? I'd really appreciate if you could provide a step-by-step guide on staking Aptos. Thank you!