I have an old 5 s, how do I reset the icloud and password?

You need to know the Apple ID and password. See: Turn off Find My iPhone Activation Lock - Apple Support

If it is yours and you have forgotten it, see: If you forgot your Apple ID - Apple Support

If it is the previous owners, you will need their help. If you cannot obtain that, the device is useless.

If activation lock is enabled on the device you will need the previous Apple ID & password. Perhaps one of these articles will help:

If you forgot your Apple ID - Apple Support

If you forgot your Apple ID password - Apple Support

If you are the ORIGINAL owner and have a proof-of-purchase, Apple may be able to reset the device for you. You will need to make a reservation at a Genius Bar in an Apple Store or obtain online support. Either way:

Genius Bar Reservation and Apple Support Options - Apple