You can port over a lot of C# code into Godot, but there are things that are engine specific. However, they are similar enough that you can just work on refactoring without sgarting from scratch.
I’ve ported a few of my projects from Unity and it’s not impossible, it’s just a lot of copy and pasting and making a few changes
That’s good to hear! I’m thinking of learning Godot, so that means all the knowhow is transferable, yay
While it would potentially be easier to learn all the not-programming stuff that’s different whilst sticking with a programming language you’re familiar with, I would recommend also having a play with GDScript too. It’s well documented and pretty easy to get started with (syntactically it’s basically Python.)