To add what Bino said
At AActor class BeginPlay() only calls blueprint BeginPlay event, so if you miss it you will break that blueprint event, but actor should work anyway (main actor initiation code is in other more impotent events). In higher classes you might break more things so you should always call Super::BeginPlay() anyway, for safety you should call parent function on every function you override.
In C++ in normaly you would need to type parent class name insted of “Super” (and you can still do that, that is even better way to access deeper parents), Super let you automatically target class parent