Note that many tax treaties discuss both educational awards and funds received for personal services, with more favorable conditions attached to educational awards. You will need to convince your school that your scholarship or fellowship should be classified as an educational award and not as funds received for personal services. To get a visa approved, you will need to demonstrate that you have sufficient funds to pay for the first year of study and that you have resources available to cover the rest of your educational program. If you don't have the resources necessary for study in the US, you will not get a visa. There are numerous restrictions on employment by foreign nationals, and some types of visas prohibit it entirely.
Most international students are limited to on-campus employment.
You should know where your money is coming from before you jump on a plane. Several schools require proof that you have enough money for the entire course of study, because too many international students are forced to return home after only a year of study. You will need to submit this form with your application for a student visa to the American embassy or consulate. This form requires them to pay your expenses if you can't. Required International students should note that in addition to tuition, fees, room and board, and living expenses, they will have to pay for health insurance.