If you are using Linux or a newbie that these commands will help you a lot when working on Linux terminal.
1. To get a full path for the current directory
$ pwd
2. To move around
$ cd # go $HOME
$ cd /path/to/another/fodler # move to another directory
$ cd .. # move one back toward root
$ cd - # cd into the previous directory
3. To list the files and sub-directories in the directory
$ ls # list all
$ ls -la # list all,including dot files and dirs
$ ls -l # long form
$ ls -hl # long form, human readable
4. To create/remove a new folder
$ mkdir name_folder
# creat a new folder
$ mkdir -p name_folder # make nested folder
$ rm -f name_folder # remove a folder
5. To print the contents of files
$ cat file_name # print file with no line numbers
$ cat -n file_name # print file with line numbers
$ cat file.txt | wc -l
# count the number of lines in a file
6. Copy a file/directory to another place
$ cp file_name to_new_place # copy a file to a new place
$ cp -r dir1 to_new_place # copy a directory to a new place
7. Copy a file / directory from a remote server to local
$ scp -rf username@ipaddress:file_name/directory to_local_place # copy a file/directory from remote server to local
$ scp -rf file_name/directory username@ipaddress # copy a file/directory from local to remote server
8. To add or remove permissions from files or directories
$ chmod 000 file_name # revoke all permissions
$ chmod 777 file_name
# grant all permissions (rwxrwxrwx)
$ chmod 755 file_name
# reserve write access for the user
$ chmod +x file_name # make an executed file
Please read more here
9. To change the owner of a file
$ sudo chown someuser:somegroup your_file
10. To access to a remote computer
$ ssh username@ipaddress -p port_number # default port number is 22
Thank you for reading!