Young Student Move to Beijing

Hi All!
I am currently finishing my BA degree in Interior and Spatial Design and have been thinking about moving to Beijing. I have a few hesitations, however. I am looking for some advice and I thought it would be the perfect place to ask here! I have minor family connections in Beijing and I have been told that it would be best to learn Mandarin first and teach English alongside that to earn some money. My tutors (who are from Hong Kong) recommend that I go straight into a design-based job because it would be a waste of my degree - the market is competitive enough apparently, and if I stay in Beijing for a longer time I will learn Mandarin regardless. I also eat predominantly vegan (due to some serious allergies and health reasons) and in general I am quite sensitive which makes me worried about the pollution there? I know this is a lot of questions to ask but I would appreciate it so much if there are any of you have Beijing experience and can give me some advice! I've heard a LOT of good things about Beijing there are just some things that I am a bit worried about and want to clear up sooner rather than later.

Thanks a lot!