Below are various resources that may be helpful to understand the tech stack used in VCal.
The link above is to the documentation for React. Unlike others, the documentation for React is very beginner-friendly and easy to read. In this documentation, you will find an easy introduction to 95% of the concepts that will be used in any React project, like states, components, conditionals, lists, and more.
The link above gives an introduction to many HTML concepts like links, styling, headings, format, lists, images, etc. It also has a CSS section for those unfamiliar with it.
Gives a more comprehensive introduction to CSS, the root language used in web development for styling, display, and aesthetics of the webpage. The link shows how CSS allows you to control the dimensions, colors, positions, etc of a web page's visual interactions.
Gives an introduction to MongoDB with its JSON document database format.
Overview of Google OAuth.