Basically you need a modeling and a texturing software. For modeling you can use 3ds , Maya, Modo, etc. or use Blender if you dont want to spend money, and you’ll need Photoshop(or Gimp, which is free) to prepare your textures. Once you prepare your models and textures you import them into the engine and create those animations and scenes. You won’t need an animator i think since there are no character animations from what i see in those example videos. Epic also gives us a ton of free assets but i dont know how much of them you’d find useful so you should get UE4 for one month, check out the free assets and then decide if you need to hire a modeler or not. You will still be able to use the editor if you decide to cancel your subscription for as long as you wish.