Dynamic IP addressing enables a variable IP to be used in placed of a fixed IP, making the "bookkeeping" tasks involved in networks, and the Internet, much more manageable.
A single IP address can be used to represent an entire local area network (LAN) on the outside. Internally, a range of addresses can be generated dynamically for the devices on the network.
TIP
You'll need to use the new IP to open the device's administrative program after it has been changed.
The firmware in your access point can be updated if it becomes dated.
Authentication is the process of verifying users; encryption means encoding actual transmissions.
Unless you can justify a WPA server on your network, you should use WPA-PSK. Or if some of your devices don't support WPA-PSK, use Open System WEP authentication and encryption.
You can use your access point to expose services and administrative functionality to the Internet.
You can block specific users from using the Internet and all users from accessing specific sites.
If you want to use a standalone router, and plug your Wi-Fi access point in to it, you should disable DHCP in the access point (if it provides this functionality).