Top 50 Linux Commands You Must Know as a Regular User... 

1. ls - view contents of directory (list)
2. pwd - path of the current directory
3. cd -  change directoryn
4. mkdir - make new directory 
5. mv - move files / rename files
6. cp - copy files 
7. rm - remove files
8. touch - create blank new file
9. rmdir - delete directory
10. cat - list content of file to terminal
11. clear - clear terminal window
12. echo - move data into a file
13. less - Read text file one screen at a time
14. man - show manual of Linux commands
15. sudo - enables you to perform tasks that require administrative or root permissions
16. top - task manager in terminal
17. tar - used to archive multiple files into a tarball
18. grep - used to searching words in specific files
19. head - view first lines of any text file
20. tail - view last lines of any text file
21. diff - compares the contents of two files line by line
22. kill - used for killing unresponsive program
23. jobs - display all current jobs along with their statuses
24. sort - is a command line utility for sorting lines of text files 
25. df - info about system disk
26. du - check how much space a file or directory takes
27. zip - to compress your files into a zip archive 
28. unzip - to extract the zipped files from a zip archive
29. ssh - a secure encrypted connection between two hosts over and insecure network
30. cal - shows calendar
31. apt - command line tool for interaction with packaging system
32. alias - custom shortcuts used to represent a command 
33. w - current user info
34. whereis - used to locate the binary, source, manual page files
35. whatis - used to get one-line man page description
36. useradd - used to create a new user 
37. passwd - used to changing password of current user
38. whoami - print current user
39. uptime - print current time when machine starts 
40. free - print free disk space info
41. history - print used commands history
42. uname - print detailed information about your Linux system
43. ping - to check connectivity status to a server
44. chmod - to change permissions of files and directories 
45. chown - to change ownership of files and directories
46. find - using find searches for files and directories
47. locate - used to locate a file, just like the search command in Windows
48. ifconfig - print ip address stuff
49. ip a - similar to ifconfig but shortest print
50. finger - gives you a short dump of info about a user