Suggestion :- use OVH servers , they are made for gaming servers
Anyway follow this step
Steps :-
1. Buy a instance with good specs
2. Login to SSH terminal
3. Wheather you can install a open game panel which include FTP , FILEMANAGER , extra feature and one-click game server installation or if you dont wanna use OGP than directly install CS 1.6 server with STEAMCMD
4. Open ports in firewall like 27015,27016
5. Install amxmodx and metmod
6. Run the server
If something left than please correct me