Backpacking from london to beijing, any advice?

i'm a 17 year old girl from new york city. i am a big supporter of operation smile and am used to traveling to a lot third world countries alone to help kids with cleft palates. each year an international conference is held in august, the 2011 conference is in beijing, china. i am over in london and paris frequently cause of my moms work and would like to travel from probably london or paris to beijing. i would like to do europe alone, i am responsible, not a party animal at all, i rarely drink anything and just want to go for the culture and life experience. what cities/countries should i visit in europe? and do you think it would be safe for me to visit them alone? after finishing in an eastern europe country, probably poland or something, i am flying to bangkok to meet up with my friends that live there and head north through cambodia vietnam and finally china. i have to be in beijing the first week of august, and i get out of school the second week of june. could i do this in like two months? i dont need to see absolutely everything because i want to see new things when im older but just some cool safe cities in europe? thanks !!!