Internship of 6 month

I am applying for an internship of 6 months and I was wondering what Visa do I need. What are the forms that I need to fill in and do I have to go in person to the Chinese Embassy in Bucharest (as I am a Romanian citizen) or can I submit the application online (and if so, what is the exact website?)? Do I also need to submit my work contract or an invitation from the Chinese company when applying?

What about flight tickets or housing information? Do I need to have them as well when applying? Thank you very much!