I am stuck with the steps to be used to build a project with the Gemini API. The backend structure and requirements feel incomplete as a beginner in backend development. What should be the must-have when using a non-relational database like MongoDB, and how do you configure it in VS Code? What can be the essential paths/URLs to build in backend development, like login and signup for authorization and authentication? How to use 2 api at once: one is user api created using thunderclient and the Gemini API used be used like other popular apikey like newAPI and WeatherAPI or there is a different method to use it in the code where I want to check whether the resume is according to the job descrpition or not . How to take pdfs as Input in react