#Login to a terminal on the pi and run
sudo raspi-config
Change the password for security reasons this should be the first option
Change the hostname to what you want the hostname to be
Change the Boot Options to be Desktop/Cli → Console Autologin
Change localisation Options to be appropriate
Interfacing Options → SSH → Enabled SSH → Yes
LEAVE OVERCLOCK ALONE (For Raspberry Pi 3 - never turbo overclock a PI unless you really know what you're doing)
Advanced Options → Expand Filesystem
Advanced Options → Memory Split - make it 16 where you will be using the pi as a server and not connecting it to a monitor