If you're using C = 4180 J/Kg/K then m --> kg, if C = 4.18 J/g/K then m---> grams. And then H is always in J which you can change to KJ by dividing by 1000.
Hope that made sense :)
My advice, in the upcoming holidays, try to catchup and work your ass off. Year 12 is NOT a time to slack off. Maybe after the trials then you can slack off a bit but not now...
Don't write something like a girl trying fit in with the "popular" group or immigrants fitting into a country. Think belonging = attachment to a thing or place as well as to people. E.g. you can talk about one's strong sense of belonging to a place (e.g. a garden, a room in the house...make it...
Depends on whether you're a maths person or not. Though both chm and physics have calculations. I would say chemistry would be more worth it as most science courses in uni require it