A HYSA is not an investment, but they do offset (a little) the impact inflation. They typically work like any other savings account, but there may be a limit on the number of withdraws you can make per month.
1. How do I look up rates? -
https://www.bankrate.com/banking/savings/best-high-yield-interests-savings-accounts/2. Once I find a good rate, how do I open a account? - Go to the bank website. You can usually open an account online and transfer funds out of your current bank account.
3. How is my money protected? - An FDIC member bank has insurance of up to $250,000 per account for the case the bank fails....the full faith and credit of the US gov has your back bro. Also, you need to use good practices with passwords and use the bank's security features such as two-factor authentication.
4. How often does rates go down? - Bank rates will vary with the Fed rate changes. Some institutions move faster than others, but they all will go up and down with the Fed.
5. What institutions are good to look at for a HYSA? Do some research and go with an institution whose name you recognize and one that has a nice/easy to use website. I would not chase the highest rates with no-name or small online only banks. Be sure to look at minimum balance requirements and make sure there are no maintenance fees. Don't be afraid to ditch them if you don't like something or if the rates are no longer competitive. I also like banks that make it easy to transfer funds OUT to other institutions......For example, transfer an amount from the HYSA to my checking account at a different bank. That should be easy with no fees.
If you are one that runs into trouble and problems at every turn.....you might focus on what is local to you. For example, a local credit union might have CDs that would pay better than a HYSA. CDs do typically have a penalty if you cash them in early.....but with the ones I've seen you can get your money at any time if there is an emergency. Or you might be able to find a decent (maybe not the highest) HYSA rate with a bank or credit union that has local branches.
The above is not financial advice....just some thoughts.