How elementary are we talking? Are specifically want to exercise stuff you already learned or also learn new stuff? My first encounter with Japanese was Text Fugu and I consider it to be pretty good for the real basic stuff.
Other than that, how about reading NHK easy? You could also sign up for the Satori reader beta.
Two years is very reasonable for WaniKani. At my current pace I will hit lvl 60 just under 2 years. And yes, it will only teach you to recognize kanji and come up with their "spelling". Sure you will be able to write the basic stuff anyway because you see it so often, but if you really want to write per hand, you have to study this extra. If all you want to do is read, this is fine, but being able to write a Kanji will help you immensely with recognizing it, that's why I just started to also practice writing.
Also you'll need to learn vocab, WaniKani only teaches you about three words per Kanji, which is not nearly enough if you want to read any native material, even stuff aimed towards children.
For grammar I advise you to buy textbooks. What I did is Genki I -> Genki II -> Tobira and now starting Shin Kanzen Master N3. For the absolute basics I would recommend Text Fugu:
http://www.textfugu.com/ It's pretty well written and teaches you a lot of other useful thinks which will come in handy with your further studies (for example how to set goals).