This is the beginning of learning Japanese: Japanese consists of three scripts; Hiragana, Katakana, and Kanji. Each script has different roles and can be seen in a single sentence.
It´s highly recommended that you avoid using the Roman alphabet while learning Japanese. There are two big reasons; Native Japanese speakers don’t use them in everyday life, thus they are not communicable (1). Most guidebooks adopt Hiragana to teach Japanese, (except for some entry level materials). Therefore, the Roman alphabet can only take you so far (2).
Hiragana has 46 letters and represents Japanese sounds like the alphabet. In practice, hiragana is mainly used for grammatical purposes, such as particles and conjugations (*you will see them later), and colloquial expressions. Moreover, this is used for beginners who have not learned kanji yet.Therefore, you must learn all of them at the beginning. Don’t worry. Hiragana is not difficult to master.
Katakana has also 46 letters. The sounds are exactly the same as hiragana. Katakana is mainly used for onomatopoeia and loanwords, i.e. things that originally didn’t exist in Japan. Katakana doesn’t have to do with speaking Japanese, but it frequently appears in everyday life particularly restaurant menus, grocery stores, signs, and workplaces.
Kanji is one of the reasons why beginners feel learning Japanese is difficult. The number of regularly used Kanji is 2,136, which is defined by Japanese government. In fact, nouns, stems of verbs, and adjectives are usually written in Kanji. However, you DON’T have to memorize all of them. You can learn them step by step. For example, when you try to take JLPT N2, which is considered as upper-intermediate level, you need to know approximately 1,000 Kanji. An important note is that kanji is used to distinguish between the many Japanese homophones. This word; はし can be either “箸: chopsticks”, “橋: bridge”, or “端: edge”.
First, you learn basic Kanji with pictures. The number of Kanji you will learn at the beginning is about 20 to 30, which is enough to establish a general knowledge of kanji. Then, when you encounter a new kanji, you look it up and make a flashcard in Anki.