PVC Conduit to Penetrate Metal Building

[TJanak]

I'd like to bring PVC conduit (2"?) with UF cable into my metal building to feed a sub panel. I'd like to come through the sheet metal wall (R panel) a few feet above ground. What is the most secure and weather tight way to do this?

I'm thinking of using flexible non-metallic conduit from the main panel (on pole) which is 20" from the metal building wall.

Thanks