Looking to make friends through western Europe..

[Countzero]

My girlfriend and I are traveling for three months through western Europe around June 1st. I have lived in Italy years ago (when I was too young to appreciate) and she has never left the country before.

Our plans was
may 23rd london
may 25th amsterdam (london too expensive right?)
june 3rd paris
june 8th travel through the south of france
june 13th barcelona to stay with a good friend for 2 weeks

then it gets a bit hazy- most likely

train up through austria to berlin then fly to rome
take train down Italy then take ferry to Greece
end in Istanbul..
She comes home and I go on to Asia for another 3 months.

I am wondering if anyone is going to be in those cities on those dates? We are looking to make as many friends as possible, share campsites, use couch surfing and generally try to travel as cheaply as possible. Buying food in markets etc.

Is 60$ a day realistic? Any advice for the second half of the trip?