Diagnosing smell in car

The AC in my Honda CR-V stopped working
several months ago. I tried to self diagnosis
this unsuccessfully and didn’t want to pay to
have the car fixed since I was able to tolerate
not having AC. However, a few weeks I
started to notice a smell inside the car as
soon as I would get in, before even turning
the car on. I am unsure if this is AC related,
but that’s the latest car issue I’ve had that I
believe may be the culprit. The only other
thing that has changed is I moved to a much
much more humid area ( CT to DC)  and I no
longer drive my car on a daily basis. I will
usually walk to work do my car is usually
sitting for at least a week. I need help
diagnosing the smell. My girlfriend had
mentioned it smells somewhat sweet, but I
don’t think that’s really the smell. If you think
it could be mold or a antifreeze leak, please
suggest in ways to self diagnosis since I
would prefer to not bring to a mechanic
without a issue identified. If you think it may
be something else please let me know.