I just reached Level 3. It’s been fun so far. But I’m not sure what this is doing for me. 
I am wanting to learn Japanese. Is this just helping me to know some Kanji? Every once in a while I see a Kanji that I know, but I don’t see how that really helps me. Should I be doing something else to learn, as well?
Like I said, this is fun. I just am not sure what I’m doing.
atarihomestar
WaniKani teaches kanji and some vocabulary. You need to know on the order of 2,000 kanji to read Japanese proficiently. This requires significant effort and a lot of time for most students of Japanese; the point of WaniKani is to provide structure and make this process easier.
You will not learn Japanese by using WaniKani alone. You will need to use other materials that include grammar and additional vocabulary, along with practice for writing, reading, listening, and speaking. This might be a Japanese course or another website with a more holistic approach instead of such a narrow focus.
I agree with everything northpilot said. A few things to add:
Completing WaniKani takes more than a year, IF you do it as fast as possible. Many people take much longer than one year to finish WaniKani. So it’s normal to feel like you still don’t know much after completing level 3. You will have to finish many more levels of WaniKani to be able to access Japanese texts like books, manga, and video games.
I recommend searching the WaniKani forums (and the internet) to find resources that other people have used in addition to WaniKani to learn Japanese. If you like SRS then I recommend a website called Bunpro as a starting point for getting into grammar and vocabulary.
The WaniKani “about” page is pretty sparse, but still worth reading if you haven’t already: https://www.wanikani.com/about
And if you haven’t, I suggest reading the FAQs as well: https://knowledge.wanikani.com
Finally, I just want to say the fact that you’re having fun is a really good sign! If you enjoy WaniKani and stick with it, you will learn to read kanji. But WaniKani alone will not teach you Japanese.
Think of wanikani as money in a vault.
The more you learn ,the more money you have in the vault. But it just sitting there.
You need to pair it with a textbook or grammar videos on youtube to use the knowledge.
For me I holistically did wanikani for the first 40 levels or so. But I was only able to use it once I paired it with textbooks and grammar videos.
You could also go full in on immersing which is another method of learning.
There are different ways to reach the same destination.
Reflect on these past 3 levels, and did you enjoy it or do you see youself doing this for a year or more.
Find what works best for you.
I know there are lots of options out there and you might get decision paralysis.
Just know what your goal is and tailor your method according to it.
Do your best. 
I am worried about “analysis paralysis” but not that much, because I have no idea what to do. Well, not NO idea. I did order “Japanese from Zero Book 1” so hopefully that will be good.
I love learning, and it’s fun to learn kanji and so I can see doing this for a while, but I think it would be fun to be able to read manga, so I need more than just kanji.
Anyway, thanks for the advice.
atarihomestar
Japanese from Zero is great. Especially Book 1 helps you learning the things that you should know before you even start Wanikani, like Hiragana. They start off using our normal characters, and slowly transition to Hiragana.
If you want to go fast with learning though, JFZ might be too slow for you cause they focus on really drilling the basics before continuing. For example, Kanji are not introduced until Book 3 (of 5).