I’m actually having a lot of fun finding patterns (heh) and making up ridiculous stories or inside jokes along with the mnemonics to memorize the radical and/or kanji. It’s pretty clever!
Gotta admit, when I first saw 山, I thought, “Oh! It’ll read as 「やま」right?”
Then I saw 「さん」and I had to remember Kun vs. On reading. Immediately went down a rabbit hole and started reading different articles on kunyomi vs. onyomi
WaniKani is a lot of fun. 
Once you get the patterns down in your head for kanji, it gets much easier figuring out which reading to use 
So push through and good luck 
That one is an easy one, it is both, but I mostly remember they call Mount Fuji ’ ふじ 山 fujisan, my friend told me it’s because it has some kind of reverence towards that mountain
All right-y, my biggest downfall to using WK on my phone instead of my laptop is having no access to userscripts.
I like being able to do my reviews at any given chance though, so I will appreciate my phone for doing its job.
A side note: I also managed to associate the kanji 生 with two things.
if you use one of the phone apps rather than the website, they have various functionality from userscripts built in ^^