Hello.
These links explain about cc and mods
http://www.carls-sims-4-guide.com/tutorials/mods-cc.php
http://simswiki.info/wiki.php?title=Game_Help:Installing_Sims_4_Package_Files
http://sims-online.com/install-mods-custom-content-sims-4-tutorial/
MC Command Center mod is a very helpful mod to use, It is safe to use, and the mod creator continually updates it. He is very thoughtful and quickly updates it after game patches, if the patch causes it to become broken.
It can be downloaded at
https://deaderpoolmc.tumblr.com
There is information about the mod in this link
http://deaderpool-mccc.com
This link thread provides help for the MC Command Center Mod. If you decide to use it and you have questions about the settings, you can post about it there, and there are helpful simmers there that will help you.
http://forums.thesims.com/en_US/discussion/913483/mc-command-center-local-help-chat-thread
After game patches are released, it is best to go back to the sites where you downloaded the mods, and check to see if there are updated versions of the mods released. Cc/mods sometimes get broken by patches. There is often a thread in the cc/mods section of the forums that lists broken and updated mods
http://forums.thesims.com/en_US/categories/mods-bugs-issues
It may help to have a look at the threads in the cc/mods section of the forums and see the sites/mods/cc that fellow simmers use.
http://forums.thesims.com/en_US/categories/the-sims-4-modding-and-custom-content
Make sure that you have a antivirus and firewall program installed when visiting cc/mods sites. Don’t click on pop up ads. Scan cc/mod files with your security program, before installing the files.