The only A330 in my menu is the A330-200RR. There is no -300. Can someone plz shed light here and help me find the -300?

Confused!

After you select the A330 there is a button in the lower left part of the screen that says Configure.  If you click on that button, you can select the variant such as the -300.  In this screen there are also a number of things you can do with boxes on the top of the screen:  Livery, Fuel and Payload, Identification.

I personally like this approach since the initial aircraft selection screen is less cluttered.  Hope this helps.

It helped indeed. Thank you. This is a whole new learning curve!