I've have tried to install some mods, and so far I have two mods. But then suddenly when I download some and put the data folder under data, it doesn't go under data files, when you start Skyrim, anyone know what it is?

Use a mod manager like NMM or Mod Organiser, rather than manually.

Are you using NMM, Steam Workshop or Wrye Bash?

I am using nexus mods and when I intall I do it with manually.

Install mods with a manager. Whether NMM, Wrye Bash or Mod Organizer but always use at least one of those.

Use a mod installer Nexus Mod Manager or Wrye Bash.

Edit : Ninja'd twice

Okay, now I've tried to install nexus mod manager and when I start it up it just says
Error: Unable to get write permissions for: C:/Games/Nexus Mod Manager/Skyrim/ Install Info.

?

Did you install the Nexus Mod Manager in that directory? This is a UAC issue stopping the ini file from being written.

It says that I need to move the install info out of the program folder?

But when I move it to the users folder, it just say the same thing again? What should I do?

https://support.steampowered.com/kb_article.php?ref=7418-YUBN-8129

For manual mod installations, don't put the archived DATA folder into the Skyrim\DATA folder, otherwise the files end up in the Skyrim\DATA\DATA folder and the mod won't work.