Japanese is written with two syllable alphabets of 46 characters each. Hiragana carries the grammar and native words; katakana spells borrowed ones. They are the first thing to learn, and once they stick everything after them gets easier. Below: a quick game that reads each character aloud as you get it right, and a chart made to be printed.
Pick a set and see how fast you can get through it.
Writing system
Variants
Click any character to hear it. Printing gives you whichever script is showing, all three tables, on one landscape page. Switch to the other and print again for the second sheet.
The 46 basic sounds, the gojūon. Read down the columns: a-i-u-e-o, then those five vowels again with each consonant in front. Learn these first, because the other two tables are built out of them.
The same shapes with a voicing mark added. Two small strokes (dakuten) turn か into が, さ into ざ, た into だ and は into ば; a small circle (handakuten) turns は into ぱ. No new shapes to learn.
A small ゃ ゅ ょ written after an i-row kana. The two characters are one syllable: きゃ is kya, not ki-ya. A full-size や would make it two.
ぢ and づ are faded because they are rare: they sound identical to じ and ず, and turn up mostly where a compound voices a syllable, as in 続く (つづく).
Hiragana first, on its own, before touching katakana. The two look alike enough that learning them together blurs both, and hiragana is what you will actually read first.
Work in rows rather than all 46 at once: あいうえお, then かきくけこ, and so on. Play only the rows you have covered so far, not the whole set. Being shown characters you have never met teaches nothing and only drags the result down.
You know a character when the sound arrives before you have thought about it. Until then the romaji under it in the chart is a crutch that quietly slows you down, so drop it as soon as a row starts to stick. Reading anything real, even a menu or a song title, will do more for the last stubborn few than another pass through the table.
Once the characters are automatic, the useful next step is reading words rather than single sounds. That is where an app that keeps track of what you have met is worth more than a chart. The particles come next: fifteen free grammar lessons covering は against が, に against で, and the verb endings a beginner meets first.