Cisco Connect is a support website so you don't need a password. Go to the site and enter the name of the product you need help with and see what happens next. I can't guarantee you won't need a credit card but there's certainly no password to access it.
My computer tells me that I can connect to the internet via GreenSpruce-guest with a password from cisco connect. Is this possible?
GreenSpruce-guest is almost certainly somebody else's WiFi network. Is there a business or hotel nearby named Green Spruce? In any event, your WiFi setup will show you every network that it can see, but these mostly belong to other people and are not available to you.
Even if you see an open one, with no password, be careful of connecting to it. It may or may not be a trap, trying to attack your machine or read your traffic.