This is a good opening. It is quite well written. You have a good vocabulary and the writing flows quite fluently. Just check your tenses, as you seem to switch from past to present at times. Also, check the rules for punctuating dialogue – have a look at a novel and see how they do it. Interesting scenario.
1. It was a pleasant October morning in the Nepalese capital Kathmandu city. Winter is knocking at the door and summer nearly gone. This is the peak tourist season when you don’t get a ticket to Nepal if you have not booked it in advance. [you’re mixing tense past and present. Easier to write using the past tense – for example Winter was knocking...]
2. She has been roaming aimlessly [She had been roaming]
3. be suffering from serious hangover [a serious hangover]
4. “Hello there”, new hobby?”
“Hello there, new hobby?”
5. “you mean you’re begging?!” [“You mean you’re begging?!”