If you didn't take Geog in secondary, i think better not, cause you don't have the basic fundamentals. But geog is like when you understand that chapter and you memorise for it, you will definitely do well. I assume that you are a history student. Most of my friends are taking history, i would say geog is much more easy to remember because you don't have to remember any year, maybe a few case studies and you don't have to memorise weird names... It depends on you, if you are really interested in it and willing to put in the effort, than go for it.
well i don't know anything about geography in jc but i prefer this to gsc many times over. i took elective geography in sec schl, it's utterly common sense and quite interesting, but h1 difficulty should be the real deal. nevertheless i think it should be manageable.
overall i think it's not difficult to understand the content of these arts subjects but the hard part is about the case study skills and understanding what the questions want. (and the typical, extremely limited time during the exam of course). gosh i hated my h1 econs. good luck