Much like an English one, you can see one

You can even use your keyboard as a Japanese keyboard.

In Windows you must install the Japanese language option for the keyboard and then use the IME at the bottom right of the bar to select the keyboard language and input method.

Next is to know how each symbol is written, you actually type in hiragana or katakana, but when you complete a word that has one or more kanji you get a drop down to choose the one you want