To configure ssh for your server you will need these things:

1. a something.pem file
2. somethinguser - username to log into the server
3. xxx.xxx.xxx.xxx -The ip address of the server

Next check if you have a .ssh folder in your $HOME directory. if you dont, create it using

mkdir -p ~/.ssh && chmod 700 ~/.ssh then check if you have a config file inside the .ssh directory. in case you dont have one
    
touch ~/.ssh/config
chmod 600 ~/.ssh/config

the first line creates the file. the second line adds the correct permissions

move the .pem file to the .ssh dir. then add the permission to it.

chmod 400 ~/.ssh/something.pem

then you need to edit the config file you crested earlier:

Host a_name_you_will_use
	  Hostname xxx.xxx.xxx.xxx
	  Port 22
	  ServerAliveInterval 120
	  User somethinguser
	  IdentityFile ~/.ssh/something.pem

save and exit.

Now open a terminal and…

ssh a_name_you_will_use

you will get a message, something like this one below. You will get this message only once, the first time you connect via ssh

 The authenticity of host '192.168.1.4 (192.168.1.4)' can't be established.
ECDSA key fingerprint is 6a:75:e3:ac:5d:f8:cc:04:01:7b:ef:4d:42:ad:b9:83.
Are you sure you want to continue connecting (yes/no/[fingerprint])?

Enter “yes” to this. and you should be logged in.