That wouldn't be much of a worry, Kiki, unless you were talking about someone ina very general term. Typically you would use their actual name when talking about a person, specifically (IIRC). (also, self, studying japanese, here. thanks to several different PC programs and books. )
Besides that, if you're a foreigner, they 'expect' some flops in your handling of their language.
Someone mentioned just kanji and having gender specific words? Well, there's kanji, hirigana, and katakana. Each having their own times to be used. Half wish I had been born, or atleast raised, over there. There may be alot more characters to memorise, but the rules for all the words are alot more 'strict' than say.. english. Things are only pronounced one way, to mean one thing, and spelled one way. If it sounds different, then it's spelled differently, and means something different
Once you get past the difference, it's one of the easier ones to learn as a second language (though easier still, for kids, since it's the initial language they're learning as they grow up and learn to 'mean' (as one of my books puts it).