This question was answered by @JustSomeTech:

First thing you should do, is give us some more information. We can’t really help you without knowing some details.

• What kind of services did you install?
• Do you have any logs we can check?
• Did you check the service is running?

First thing I would recommend is checking your firewall. Do you have IPTables or UFW? You need to open the port before you can connect.
IPTables:

iptables -A INPUT -p tcp --dport 25565 -j ACCEPT

UFW:

ufw allow 25565/tcp

View the original comment