Centos Operating system and Red Hat Enterprise Linux is almost same but not. Red Hat will not provide repositories for free you have to subscribe, Where as Centos provides them freely. Practice purpose and testing purpose you can simply use Centos.

Centos 7 Installation Step by Step guide

1. Introduction to Linux
2 . Linux Architecture
3. Linux Vs Windows
4. BASH Shell Features
5. Linux Directory Structure / File system hierarchy
6. Operating system boot process

Centos System Administration Topics

7. Basic and Common commands
8. Text Editors
9. Operating system installation process
10. User profile management
11. User Administration
12. Access control list (ACL)
13. String related commands
14. File links (Soft & Hard)
15. Search related commands
16. Task automation and task schedule ( Crontab & at )
17. File system / Creating standard partitions
18. Disk quota management ( user & group quota )
19. Redhat package manager/Yellow dog update module ( YUM )
20. RAID levels and it’s explanation
21. Software RAID configuration

Advanced system Administration topics

22. Networking
23. Remote Server Management
24. Network File System ( NFS )
25. Samba server ( SMB )
26. File transfer protocol ( FTP )
27. Hypertext transfer protocol ( HTTP ) / Apache Server
28. Simple mail transfer protocol ( SMTP ) / Mail Server
29. Dynamic host configuration protocol ( DHCP )
30. Domain name system ( DNS )
31. Network information system ( NIS )
32. Pluggable authentication module ( PAM )
33. Backup and restore
34. Squid proxy server
35. VNC Server
36. Recovering root password
37. Installation and configuration of NetApp MPIO software
38. Configure YUM repository for Network Installation