In Minecraft wNo addresses or names work when i pu them in Add Server. Why?

Those aren't server names or IP addresses.

a server name would have a domain in it like .com or .org, or be an IP address that consists of four octets (8 binary bits, or numbers that range from 0-255) separated by decimal points. So you may see something that looks like 192.168.0.101 (that would be an internal IP address in most networks, so don't try that as it won't work).