its depends on you what you're capable or passionate about
Most Nepalese/Indian/Pakistani people opens restaurant, convenient store or gas stations.
Restaurant - to open one you should know about food and you should be passionate about cooking. If you don't know about cooking either you have spend a lot of money hiring management staff in many cases they can take advantage and steal your money. Until you now about food or experience about Restaurant do not open one.
Gas station and convenient store : this is not that hard to open you don't need much experience, just you need to know supplier who can provide you best product in reasonable cost.

Or if you're are graduate or have degree , you can open your business according to experience and degree.
If you have accounting degree : bookkeeping or payroll business

Also online business is booming now a days. Selling in amazon and eBay. Buying in a wholesale price from Alibaba or other Chinese supplier and selling in amazon eBay for 15 to 20 Times Of its cost. You need 10 to 15k investment and can make decent money.
I am doing (not full time) and make 7 to 8 hundred profit a month.
If you can invest more time and money you can make a lot more. Always start with small. I started first with $500.