I will start this review off with the stereotypical: This trip was the greatest decision of my life and it changed my life. When I went on this trip, it was the summer after my freshman year, I had never done anything as spectacular as studying abroad and I was scared to death to leave the country. I can tell you though, if you agree with any of those things: Thailand is perfect for you.
It took about a week until I was completely comfortable navigating the city and walking around by myself.
"BUT WAIT STRANGER! My professors and parents say use the buddy system all the time" - You right now.
Yes, I agree. Don't walk around the city on your own at night or on your first day in the country, but Chiang Mai is overwhelmingly safe. I never once was afraid of pick pockets or getting mugged. I brought a lot of security items to hide money, I only ever used them when I went to the currency exchange bank when I had a lot of cash on me. Besides that, I would spend days off or time between classes walking around downtown, exploring the old city, or planning weekend get-aways around the country.
There was little to no language barrier while I was in Chiang Mai. Most Thai people apologized to me that their English wasn't better, which made me feel guilty because I barely spoke any Thai. The only time we had trouble with the language was far outside of the city and in the more rural areas we visited. We could communicate through hand motions and other things though.
Food was never an issue. Thai food is VERY spicy and not everyone was a fan of it, however, there were Italian places, burger places, and many more. So no fear for those with weak stomachs.
Some random pieces of advice I would give to someone going to Thailand:
Don't pack too many clothes and DO NOT buy your school uniform in the states. Everything is really cheap in Thailand and we got the chance to go to the university store and buy dress shirts.
Barter the price for everything at places you can barter. If you don't like the price WALK AWAY. Most people will chase you down the street and lower the price to what you want.
TRAVEL! A group of friends and I went to Pai which is about 4 hours north of Chiang Mai. We got to go around rural Thailand and see natural waterfalls, hot springs, and canyons, which were all absolutely incredible. Others went to Phuket in the south which is white beach sands and clear water, which is also beautiful. Spending a day in Bangkok is also worth the trip. The bottom line is don't spend the WHOLE time in Chiang Mai, go out and see the country!