PostgreSQL is an advanced RDBMS that deals with large datasets and are less prone to errors. Moreover, PostgreSQL delivers better results much faster as it mainly deals with short queries and is completely SQL-compliant.
PostgreSQL is an open-source RDBMS that is SQL-compliant and filled with rich features. To perform high-volume data operations with great complexity, many companies prefer PostgreSQL. Also, it supports different data types and is considered a highly matured relational database to deal with complex queries.
SQLite is a popular serverless database engine for developing embedded software for various electronic devices. It can be used as a short-term dataset, and it is capable of managing medium-range HTTP requests.
SQLite is not a programming language but a serverless database engine based on C programming. Moreover, it is a library that many developers use as an embedded database.
You can easily start with PostgreSQL as it is an easy-to-use DBMS solution. Also, it is the best choice for beginner SQL learners.