C++ Compiler error mobile/tablet

Following the official documentation on getting started with programming, compiling for desktop/console gives me no errors and works flawlessly however when I try to build for a mobile/tablet project, I get several errors which I can only assume are linker errors

1>------ Build started: Project: MyProject, Configuration: Development_Editor x64 ------
1>  Performing 3 actions (4 in parallel)
1>  MyProject.generated.cpp
1>  MyActor.cpp
1>c:\users\kalis\documents\github\myproject\source\myproject\MyActor.h(19): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\kalis\documents\github\myproject\source\myproject\MyActor.h(19): error C4183: 'AHelloWorldPrinter': missing return type; assumed to be a member function returning 'int'
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(7): error C2653: 'AHelloWorldPrinter' : is not a class or namespace name
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(8): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(9): error C2550: 'AHelloWorldPrinter' : constructor initializer lists are only allowed on constructor definitions
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(10): error C2065: 'MyNumber' : undeclared identifier
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(11): error C4508: 'AHelloWorldPrinter' : function should return a value; 'void' return type assumed
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(13): error C2653: 'AHelloWorldPrinter' : is not a class or namespace name
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(15): error C2653: 'Super' : is not a class or namespace name
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(20): error C2065: 'MyNumber' : undeclared identifier
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.cpp(20): error C2661: 'UEngine::AddOnScreenDebugMessage' : no overloaded function takes 3 arguments
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.h(19): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>C:\Users\Kalis\Documents\GitHub\MyProject\Source\MyProject\MyActor.h(19): error C4183: 'AHelloWorldPrinter': missing return type; assumed to be a member function returning 'int'
1>  -------- End Detailed Actions Stats -----------------------------------------------------------
1>ERROR : UBT error : Failed to produce item: C:\Users\Kalis\Documents\GitHub\MyProject\Binaries\Win64\UE4Editor-MyProject.dll
1>  Cumulative action seconds (8 processors): 0.00 building projects, 0.21 compiling, 0.00 creating app bundles, 0.00 generating debug info, 0.00 linking, 0.00 other
1>  UBT execution time: 3.83 seconds
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.MakeFile.Targets(38,5): error MSB3073: The command ""C:\Program Files\Epic Games\4.6\Engine\Build\BatchFiles\Build.bat" MyProjectEditor Win64 Development "C:\Users\Kalis\Documents\GitHub\MyProject\MyProject.uproject" -rocket" exited with code -1.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

this is happening for me and several other members of my group (we are working on a university project). Can anyone please advise?

Put the source in question into the post as well, difficult to let you know what could be wrong without seeing it.

This is just following the Unreal Programming tutorial here Unreal Engine CPP Quick Start | Unreal Engine 5.1 Documentation

After it not working with my own typing, i tried copy/pasting and it’s still the same thing. The code works perfectly fine when using a project for desktop, but not when trying to do it for mobile.