" I’m trying to learn Japanese but it’s very difficult."
" I'll try to get there as soon as I can. (An effort is implied)"
Try + to + infinitive means that something is difficult and you make an attempt to do it.
-How can I remove the stain from this T-shirt? It won't go!!!!
-Try using that new soap powder you saw on TV.
" Have you tried using butter instead of oil?"
Try + ‘ing’ means make an experiment. It’s not difficult – it might work, it might not.