The most important piece of advice I can ever give you is to make sure you spend more than half your time studying basic, platform agnostic things. Knowledge of data structures, concurrency, or the http protocol will remain relevant for 20+ years. Knowledge of React may be useless 3 years from now (or in 3 months if they completely overhaul some of their standards). Deep knowledge of Firebase may be short lived as well, and doesn’t transfer to other platforms. Knowledge of relational database performance/normalization tradeoffs, web server scaling, relational database scaling, and caching will serve you well in almost every project.