I was a long time Unreal 2 and 3 developer, moved out of games for several years, and then got into some non-game related Unity projects, and now I’m back on Unreal, after 7 long years.
I found this document to be invaluable, after having picked up Unity for about a year: https://docs.unrealengine.com/en-us/…rted/FromUnity
Then, as a person who is primarily a programmer: https://docs.unrealengine.com/en-us/Programming
Though you’ll also need to learn about Blueprints, as well, because they are a very powerful tool, that even if you do just about everything in code, you’ll still need to operate with blueprints to some basic degree from time to time. (they are, at the minimum, an equivalent to Unity’s Prefabs, but considerably more powerful if you want them to be. I mostly use them as a prefab, presently, because almost everything I’m doing is C++ level)
As far as learning C++, if you have good knowledge of another C-like language, like C#, as you say, it shouldn’t be too terribly difficult to kick off, but you will have to do some study on C++ itself, if you’ve never used a language that makes heavy use of pointers and other bits that aren’t in or aren’t commonly used in C#.