When I was around your level, maybe early teens, the first WaniKani Book Club started.
I was so ready to read just about anything along with others (hoping their comments would help me understand more) that I jumped head first and just joined it!

Today that Book Club is known as the Intermediate Book Club 
I was able to read about half of it before I fell too far behind and quit, understood no more than a word here and there. Yet was able to enjoy the process of it! I’m not even ready to fully read it today! But was it too early? Nah, it was still worth the experience and effort, as it was enjoyable even if I didn’t get much. The comments did help me understand what was happening in the story too.
I don’t recommend going for a book out of your league on purpose, but never back out of something you want to try cause you fear you are not ready yet. The only way to get ready is by doing, and if you can enjoy the process of reading even with lack of understanding then it is never too early (but do try to aim for something with a bit higher understanding than I did
)
I have since read a whole book that was above my level, Girl Who Leapt Through Time. Got a higher %, but no where near the 80% needed to feel you grasp it. Still enjoyed it enough for the effort to be worth it. I’ll probably try read it again later. I have also read most of Kiki twice, with 2 years between. Seeing the difference in understanding now from then is such a great way to measure your own improvement! I still need to read the last 3rd though 