i downloaded a few mods and was wondering how i get them to work in the game?

there are usually instructions in the readme, which you should always read carefully specially if you're new to mods. Generally, it is recommended to use Fallout Mod Manager (search for it on the nexus) and/or Wrye Bash. You can install manually (in most cases just extract to the install directory\data) but spare yourself future headaches and take time to learn FOMM and/or Bash