Title says it all and I need help.

Here`s the problem: I just created a new mod that basically enchants the version of an another mod (Omegared99 Armor Compilation: Battle Mage Robes) in Creation Kit. Problem is when I go to data files in skyrim launcher , it`s not there. Then I went to copy my new file to skyrim data and installed it with nexus mod manager , it did not work as well. I also heard you can create a skyrimcustom.ini file but I have no idea what to do with that.

Thanks in advance.

Make sure you saved the mod properly. Also, you can't have one mod enchant armor from another mod. You will have to move over the enchantments to the mod with the armor.

Any tips , on how to save it properly?

Press Ctrl + S. If you don't have a mod set as active, then it should ask you what to name the mod. If it doesn't ask you to name the mod and you don't have a mod set to active, then it didn't save.

I just looked up what an active file was in your 1st post and I realized that you can't save changes to the master file which was Omegared99's Armor Compilation. So what do I do?

Since the file is a master file, simply load it up in the CK (with nothing set as active) and make the changes you wish to the armor. Then click Ctrl + S (or however you wish to save) and name it whatever you want to save it as a plugin.