Is there a word that means "unsure but okay with it"?

[Monstera_deliciosa]

Equanimity?

[MrDibble]

@Raza

What about nonchalant?
The problem I see with some words like “resigned”, which are cromulent, but denote an air of disappointment, which I don’t think the OP is specifying.

Nonchalant doesn’t convey the sense of uncertainty, though.

[The_Stainless_Steel_Rat]

I would add the Arabic "In’shallah (various spellings-YMMV), which means “as God wills it”.