Hi neko,
Please don't take offense when I ask, is English your native language? It is hard to understand exactly what you are looking for from your question. However, the Japanese writing system is more complex than simply being a few letters and sounds. There are two separate syllabic scripts, as well as thousands of kanji - a pictographic/ideographic script derived from Chinese. All three of these scripts are used in written Japanese.
As you can see, it's a bit complex. If you are not sure where to start, I suggest learning hiragana and going from there. (Important things to look for are stroke order, pronunciation, and a little vocabulary never hurt!) Find a good site that works for you. Maybe something like this:
Hiragana Lessons - How to write hiragana "sa"