the first step is to learn the hiragana and katakana http://www.punipunijapan.com/ this website has free hiragana and katakana e-books so you can download them and print it out and practice all you want or you could just watch videos on how to write hiragana and katakana characters there's a lot of videos on youtube,it's not very hard you'll finish them in like 2 weeks or maybe less i finished them in 1 week
alongside with learning to write hiragana and katakana learn some basic grammar,there are some great books like Genki for beginners there are loads of books to help beginners so you can't go wrong with it
now the kanji probably the hardest thing you'll face in learning the language but once you get hold of how to write them you'll realize it's really fun,the website i mentioned also has kanji e-book that will go over 300 kanjis which is very food for a start when learning kanji with grammer i suggest going over 5 kanjis a day with the grammar
if you have any other question or you feel like i didn't clear a point don't hesitate to ask