Greetings, Shreya.

Learning CS is only as difficult as you make it out to be. If you like problem solving and are interested in learning how software are developed then no one is stopping you.

- There are plenty of online resources and books since it is a popular field so you won't get stuck on a problem for very long

- You can self learn a lot of the things in your free time (just 1 hour a day can be enough in the beginning)

- It is a simple logic based study and it's fun

Is it a good combination with geography?

That depends on your careers plans for the future, really. Geography and CS is an unorthodox combination to be honest but you are interested in both of them then go for it, as they say 'no knowledge is ever useless'. You will find your way once you get the hang of both the subjects as to what do you want to do with them. Go for CS related career, or UPSC or what gives. I'd say research more on what CS is all about and do not rush the decision.

Good luck