Colleseum of Fools question

So I just beat level 2 of the colleseum of Fools (it took me 3 days I'm so ashamed) on 6 health points and I believe 2 nail upgrades. I am excited to upgrade my nail but I don't want to return to the Colesseum until I have more health. Once I start something I won't be able to finish it (and the bugs mocking me in the crowd doesn't help...) so I just wanna ask without any spoilers of how it is at all how much I should prepare for the third level. Thanks!