First of all, learn
Hiragana and Katakana. You can spend your entire life learning kanji. There are a few people on youtube who break down grammar structure. It's really not that complicated. Something that ends in に at the beginning of a sentence is the ultimately affected thing or when something took place. は, means in relation to something and is almost ways at the beginning if に isn't present. が marks the subject (try not to confuse it with は, they mean two completely different things). を designates the object of the sentence. Participles will likely be your first real challenge and where Japanese's jigsaw/lego like qualities are apparent.
たすけて: Help
たすけたい: Want to help
たすけない: There is no help
たすけさせる: Let help, made to help
たすけられる: Can get help
there are even more
From here on, it's learning the smaller, lesser used grammar. Phrases, words, and the start of learning kanji (fuck the Chinese so much).