You’ll find info in the knowledge base on how leveling works and how to plan for the srs-timings used by WK.
Level 1 and 2 are sped up as you can read above. otherwise, the max speed is 6 days and ??? hours. I forget the exact number.
Make sure to immediately start in on radicals since those unlock the second batch of kanji. Then it’s a matter of getting 90% of all kanji to guru to level up.