The Care Bears are a group of cuddly bears who live in Care-a-lot, a magical forest. They often travel to Earth to help people in need. There's a young girl named "Cheer" who is their human friend and often travels with them.
While it's not called "The Happy Forest", Care-a-lot is a very happy and magical place!
Do you have any other details about the show you're thinking of that might help me confirm? For example, do you remember any specific characters, themes, or the time period you watched it?