Here are some general pointers
-Stay away using Romaji (Japanese people don't use it for reading.)
-Start with the Hiragana, then move on to Katakana
-Start the Kanji as soon as possible preferably right after Katakana. They take the longest.
-Use a beginner course that is already made like Japanese from Zero, Genki, Human Japanese, and etc.
You should be able start learning once finished the Hiragana.
Best of Luck!