You need to activate it. If you apply online, you need to go to the bank to activate it in person with your card and ID card. If you apply at the counter, you need to call directly to activate it. As long as it is activated, it can be used. As for whether to set a password to consume or consume with a signature, it is up to you. It is recommended to set a password so that even if the card is lost, it will not be stolen. It does not matter whether you sign in the signature column on the back of the card or not. It doesn't matter if you are free.