If someone is curious it means they are interested in learning about what is around them.
For example: "Lynne was curious to find out how many people used the website."
If something is curious, it means it's odd, strange or unusual.
For example: "The results were very curious because a lot of Americans were using the website."
If someone or something is interesting it means it gets your attention because it may be unusual, exciting, or has a lot of ideas
For example: "She found the results very interesting."
So, something curious can be interesting, but something interesting isn't necessarily curious.