Welcome, welcome, welcome!
Rightly so.
Rightly so you needn’t be.
With 10 lessons per day, your daily reviews will exceed those 20 really fast. Prepare for around 100 daily. And while lesson count does affect review count, it is not instant. It does affect the current day directly, but the next days and weeks would still bring in the bigger chunks from previous lesson batches. So it does need to be planned for.
As a rule of thumb, assuming a steady lesson count of X and 100% accuracy, your review count will slowly ramp up to 7 * X in the daily big batch. Any failed review adds 2 on top.
The initial goal timings are good though. It takes about 9 lessons per day to reach level 10 within 6 months. For level 15, you’d need to bump that to about 14 lessons per day.
I’ll also shamelessly self-plug, in case you’re not yet sure about day-to-day schedule building.
And of course the obligatory The Ultimate Guide for WK, just in case.