Visual Studio on compile - many errors that aren't valid errors

Ok so novice VS C++ user so any feedback appreciated.
I’m encountering a repeating issue whereby after making some minor edit on a project that compiled fine, I suddeny get dozens and dozens of non sensical errors after a build (Ctrl+Shift+B)

ie 'foo': is not a member of 'Afoo'

syntax error: missing ';' before '*'
on the following line
UBoxComponent* Collider;

unexpected token(s) preceding ';'
on the following line
ABall* BallRef;

It’s a very simple Pong tutorial I am following.
There must be something major and obvious that is set up wrong in my project.

Any tips or feedback appreciated!

My guess, your includes are not setup correctly. Cleanup your includes and/or use unity build settings.
Have you checked the build options in MyProject.Build.cs?

bUseUnity = true;

Are these actually errors preventing you from compiling, or just IntelliSense errors? Only worry about errors you get in your Output log. IntelliSense can’t understand macros, so these lead to a bunch of false errors all the time.