I would like to learn japanese; I can teach you english/french

well I can't really teach you since I'm trying to learn Japanese too. But just so you may know, to proofread your post:



Minasan, konnichiwa (backwards is awkward). Watashi wa nihongo wo benkyoushiteiru[or -teru casual]. Oshiete kudasai (this is weird you wouldn't say "Please teach me." so suddenly).



Also, I strongly recommend anyone who's studying Japanese to learn Hiragana and Katakana as their top priority. Then don't ever use romaji again. For me, it took around three hours of my time to read them, a little longer to write them. Romaji will be your greatest obstacle if you keep using it.



In Japanese script:



皆 さ ん 、 こ ん に ち は 。 私 は 日 本 語 を 勉 強 し て い る 。 私 に 教 え て い た だ け ま せ ん か (very polite)。