I will suggest Python as your first language. It's easy to use, powerful, and it's being heavy developed. It also has a huge user-database, which makes it easy for you to find articles, guides, tutorials, libraries, documentation, and so on. It's cross-platform and will therefore also work on Linux.
You can find the official Python website
here. On that website you can also find materials for beginners in the language, and the official Python implementation, so you can get started right away.