Adding a map cycle will make it so a specified list of maps on your server are cycled between matches. This saves you the time from having to manually switch the map each round. You can also add any workshop maps that are on your server to the map cycle.
1. Open the File Manager
2. Navigate to /steamcmd/cs2/game/csgo/
3. Right click a blank area and create a new file called mapcycle.txt
4. Right click the file and click Edit
5. List each map that you would like. All maps on your server can be found in /steamcmd/cs2/game/csgo/maps/
6. Restart your server