if by something online that I more then whats in ur checkings but u have enough in ur savings will u get overdrafted?

If you have set up an "overdraft" coverage you are safe.
If you did not link the accounts you will be charged ISF (Insufficient Funds) fees by the seller AND your own bank (around 50$±) for troubling them with the transactions. ALSO, some banks have the dirty trick of "redepositing" as gesture of help, which DOUBLES the fees.

Best to transfer the money to be safe.

Depends on the operation of your particular bank, I would not count on automatic fund transfers between accounts.

Yes you will because the savings money is NOT in your checking account. Transfer that money first to avoid the overdraft fee

it all depend how you originally set up when you open the account apparently you don't remember best ti talk ti bank not a stranger