Well for me, i studied Hiragana and Katakana before venturing into Wanikani so i cant say much. However, if you master that (which i think its tons easier than any kanji) your life would be easier because you can read the readings easier. So i would suggest you to master both first.
Also, radicals tend to be easier, BUT (a big BUT) its very useful in the subsequent Kanji Section. Its not always 100% good so i kinda make up my own mnenomic time to time, but it does work.