Due to heavy traffic, my website sometimes gets down time or loads really slow. How can I solve that problem? If I get another server, will it help a lot? I am currently using WHM/cpanel dedicated server How can I set this up?
Yes it'll help. Get another server, make another Domain host/nameserver at your domain registrar's website using your new servers IP. Then add the newly created nameserver as nameserver #2 for your high traffic website
No, you just to need to copy all the files. Then configure your scripts to connect to the database on your first server. You can do this by replacing localhost in a database configuration file with the IP address of your first server.