Most monsters only have one, perhaps two elemental attacks, so while element resistance can be huge for some fights, it's utterly meaningless in others. ESPECIALLY if you're fighting a monster that doesn't even use that element in the first place.
You'll get a better idea of what your playstyle is and how to emphasize your strengths/buff up your weaknesses as you go along, so don't sweat it at this point. I was just curious.