Sikkim+ Darjeeling in May end/ June beginning

Dear travellers, I am a 28-year old seasoned traveller from Delhi who has decided for Sikkim and Darjeeling to cover places, famous darjeeling toy train ride, maybe one or two treks and other activities. I am a bagpacker and use public transport as much as possible and prefer budget guest houses/ homestays to hotels. People of any age, gender, ethnicity, religion and background are welcome to join me for this journey. I have not decided the dates, so we can finalise that by mutual convenience.