That sounds like a big project. Start with one small sector, and then expand your business.
My suggestion (if you are really serious) to you is get some land on the outskirt of Kathmandu ( for cost reason mainly, if you want to expand later look for one with bigger open plot alongside) and start with organic farming of vegetables ( like by not using pesticides). Reach out to local restaurants that cater to people who like quality produce). You will be helping the economy by employing local people. make sure you pay them good lol.