either you don't have An internet connection or you have a cracked account on minecraft and it wont let you on. The alternative to this is their minecraft server was having issues.
Type in the IP address or Hamachi address of your friend's correctly or play the premium Minecraft. Myncraft1: Your friends has to be on (Hamachi) to connect to his server
it is a private server
A cracked Minecraft server is a server which doesn't connect to Minecraft.net, which means that you can use it without an activated premium account. However, cracked servers are illegal, and WikiAnswers will not provide guidance for illegal actions.
To connect to any Minecraft server you have to know and input their IP address when it prompts you.
no you have to have a payed account witch is not bad its 20 dollars for life and the price may change soon
Just run the java script. If your on windows start the minecraft_server.exe. These can be downloaded on the Minecraft website. Check the MC Wiki for more detailed information.
Some servers have a "whitelist" that you need to be on to get into the server. These are also called private servers. To get onto a whitelist, you need to contact the people in charge of the server and ask them to add your minecraft name to the whitelist. If they do, you can now connect to the server by using the IP.
It may not be stable
There may be several reasons you would be unable to connect to your own server on Minecraft. First check to make sure you have not typed in the Ip address wrong. Second, make sure you are running the latest Minecraft server software(You have to download a new version after every Minecraft update). Thirdly, you cannot connect to a server using the computer that is running the said server.
Check the Minecraft Wiki. It has information there.
You need to have a upgraded account to have a Minecraft Server running on 000webhost.