There are several things to consider when looking to research the political, social, and economic factors that Spain and France had for colonizing different parts of the world. I will share some ideas to consider and provide some reference links for you to examine.
When dealing with economic issues, you should consider concepts like money and resources. What resources did these countries want or need? Why would money be a part of this decision-making process? How could obtaining colonies lead to more money for France and Spain? For example, both Spain and France had kings that lived extravagant lifestyles. Colonies would help subsidize that way of living. These kings were constantly looking for more money.
Regarding political issues, there are a few ideas to consider. How would each country be viewed politically if it had colonies? Was lack of political freedom a factor in wanting to gain colonies? Would colonies make France or Spain stronger politically? For example, Spain, France, and England were rivals. Each country wanted more power and control than the others.
For social factors, I would ask a few questions. Did either country believe it was their right and/or duty to spread their way of living? Did they believe their culture was a superior culture? Did they want to act like missionaries and spread a specific religion? Was religious freedom a factor in wanting to get colonies? For example, these countries tended to believe they had a superior culture. Spreading that culture was a priority.
These are some questions to consider when researching the various factors why Spain and France wanted colonies.