The pros of learning French are that you can then use French. The pros of learning Spanish are that you can then use Spanish.
To decide which language to use, you might consider:
- Which language is more useful to you right now, or in very near future?
- Which language is more useful for you in the long run?
- Which language can you more easily practice at the moment? What about in the future?
- How motivated are you to learn the languages?
- How easy it is to learn the languages?
- Your purpose for learning the language.
Only you can answer these questions in your circumstances, and only you can weight and prioritize them.
For immediate use: Are there people around you who use the language? Are there books, movies, games and so on that use the language? Do you know someone who speaks the language?
For long-term use: Are you willing to move to areas where the language is used? Can you make use it for seeking employment or while working if your future career (or studies)? Some media you eventually want to understand in that language? Anyone in your family who uses the language?
Practice should not be an issue with Spanish or French, both being huge languages. Maybe check out if you can find a language café or similar where you are; it might reactivate after corona.
Motivation is distinct from the intellectual reasons you might or should be motivated, as above. If you have an inherent motivation or preference, do not disregard it.
For difficulty, both of the languages are difficult and easy in slightly different ways; any detail on this should be a separate question.
For purpose, it could reading, watching movies, living your life in the language and moving to a country where it is spoken, or maybe learning about the culture. Would you learn Spanish and French for the same or different reasons? If different, is one them more acute now? Is learning one of them for that particular purpose easier than learning the other?
But, in the end, the choice is yours.