First questions first: do you know how WK works?
When you level up, you unlocked a LOT of stuff. Do the radicals first. This will allow you to guru it on your 4th day, which will unlock the second batch of kanji for the level.
The kanji that you unlocked upon leveling up can be started from anytime between completing your radicals and unlocking the second batch of kanji. (I usually do them as soon as I have time, but this is what’s needed to level up quickly.) --> these kanji will be guru-ed somewhere between your 4th and 8th day.
After guruing your radicals, learn the second batch of kanji asap, which will allow you to guru it on your 8th day and leveled you up
If you already know all these, pardon me. I somehow had to find out on my own (wasn’t much in the forum in my early levels) that you don’t have to do all the lessons to level up quickly, just the radicals and the 2nd batch of kanji. It helps you prioritise when you don’t have much time (have to go to class, work, etc.)