How to select my first company? On the basis of salary or opportunity to learn new things?
A perfect balance of both will give you job satisfaction. Try taking the job which pays you as per the time you are devoting to them. As you are at an initial stage, you have time to explore, learn and grow.
Even if, after joining a certain company, you are not satisfied with the job role or work culture, consider it as a good experience. Just keep an open mind and think rationally before making any decisions. Maybe consult a career counselor for better guidance.