Welcome to WaniKani! And really cool that you want to be part of the community 
I see that you have some previous knowledge. Nice! What did you do earlier? (Just curious)
By the way: There are many ways to modify your very own WaniKani. These nice little tools are called userscripts (just search for userscripts in the forum). You CAN use them to cheat, so some people are afraid to use them. For me these nice little tools make WaniKani from a 8/10 to a 10/10!
So for this little mistakes (I often say the correct Japanese word loud, but type somthing completely different) there would be the very useful script Double Check.
And guys: please don’t scare @dpuza away. The effort of WK is very managable and you can decide on your own how fast you want to progress. IF you want to rush through WK, you CAN do 1 Level in one Week. But you abolutely don’t have to! Many people do 1 Level in 10 or 12 days and they are abolutely fine!
~T 