To endorse the check, you'll just have to flip it over and sign the line with the x to the left of it. This line will be found at the top of the check, and you'll sign it sideways. Do this right before you go to the ATM or the bank, so that your check cannot be cashed if you lose it. If you don't endorse the check, that makes it harder for the bank to accept it from a person who wants to cash it for ulterior motives.
FDIC insured means that the government will give you your money back (up to $100,000) in case your bank goes out of business and can't pay you. If you have more than $100,000 to put into savings, try spreading it out over several FDIC banks with no more than $100,000 in each account.
The Federal Deposit Insurance Corporation (FDIC) is a government agency designed to protect consumers and the U.S. financial system. The FDIC is best known for deposit insurance, which helps customers avoid losses when a bank fails, but the agency has other duties as well. Deposit Insurance