UE4 uses many macros, and Intellisense is not particularly good at understanding all of them; those aren’t errors, it’s just Visual Studio trying to be helpful.
If your project compiles without errors, then your project is fine (aside from other logical problems, nullptrs, and other problems that don’t throw compile errors).
As you work more with UE4 in VS you’ll get a sense of when intellisense is just wrong and when it’s actually telling you something important.
In general, when compiling, it’s best to ignore the “Error” tab and rely on the “Output” tab to evaluate the results of your compile. The errors generated by VS are often misleading and, frankly, wrong.