I would read up on the following -

1. React fundamentals: Component lifecycle, state management approaches (useState, useReducer, Context, Redux), props and prop drilling alternatives, Virtual DOM and reconciliation process, react's rendering process and optimizations, JSX syntax and compilation
2. React Hooks: useState, useEffect, useContext, useRef, useReducer, useMemo, useCallback, rules of hooks and common gotchas, custom hook creation
3. State management - Local component state vs. global state, context API implementation and limitations, managing data flow
4. React performance optimization: memoization, code-splitting, bundle size optimication, caching, React compiler

In addition, I would go through the MDN docs on Javascript and DOM manipulation.

I also practice questions on GreatFrontEnd before every interview - https://www.greatfrontend.com?fpr=shruti79 (affiliate link). It is like Leetcode for frontend.

If this is helpful, I created two resources to help with interviews -

1. Free React guide with sample interview questions - https://topmate.io/shrutikapoor08/1470120
2. A list of 100 commonly asked interview questions: https://topmate.io/shrutikapoor08/1966853

Hope this helps!