How do I connect to WiFi on this iPhone 5s

If you know the network you want to connect to, Settings->Wifi, pick the Wifi network you want to connect to, and input the password in the field for it when it requests it.

The security type is automatically determined based in the network you wish to connect.

We cannot tell you what network to connect to. Only you can know what Wifi network you have the passwords for.

Are you at home, or office or somewhere else when trying to connect to a Wifi network?

You would connect to your own network (the one from your own router) if you are at home, or a known network when in your office or some other place.

If you have other devices or computers, what Wifi network are they connected to?

What wifi network are other people around you connected to?

Only you can know what Wifi network you can connect to. We cannot tell you this, as its entirely different for everyone.