In an email I want to send to school where I work is this correct to ask 'any news for new courses?' can I say courses or better to say classes? is preposition for correct?
For isn't incorrect, but it's also not very specific.
If you're trying to find out if new courses have been added to the schedule, then I would say this:
Do you have any news as to whether new courses have been added?
Or if you're trying to get news about new courses that definitely exist:
Do you have any news about the new courses?
It's probably better to use courses, because classes is a very general term. For example, a class could be an entire course, or it could be a lesson from a single day.