How do you download mods once already downloaded forge?

After downloading and installing Forge, you can download mods from websites like CurseForge or Modrinth. Once you've downloaded a mod (usually a .jar file), place it in the "mods" folder located in your minecraft directory (typically under .minecraft). Launch Minecraft using the Forge profile, and the mods should automatically load. Make sure the mods are compatible with your version of Minecraft and Forge.