Hi JC LEON,
Just like Sean said, I also highly recommend starting with UE4. All those tutorials you bought are never a waste. Watching those tutorials (materials, matinee, cascade etc) you can recreate most of them in UE4. Besides UE4 support is huge. If you hit a dead end, this community (including UE4 developers!) is always here to help you out. 
I’ve been an avid UDK user but now i only use UE4 and trust me, UE4 is far far superior and powerful and easy to work with. Even though UDK knowledge is always good its not required. You can easily create games with Blueprints if you dont like C++ or if you are an experienced C++ programmer you can even modify the engine to suit your needs or integrate other middlewares!
So in short…Go with Unreal Engine 4. 