How to clean log files in Linux

Fisrt, See the logs that are in the logs area of /var 
 du -h /var/log/ 
 The du command prints the estimated disk space usage of each file and directory for the path that you specified. The -h argument causes the command to print the information in a human-readable format. 
   
 https://linuxhandbook.com/empty-file-linux/ 
   
 https://support.hostway.com/hc/en-us/articles/360001972270-How-to-clean-log-files-in-Linux