I big recomed for me is Gamemaker. I'm studying game design right now and i have used both Gamemaker and Unity. Unity is fun and able to do both 3D and 2D but the simplicity of Gamemaker makes it perfect for beginners. 3D is very challenging in Gamemaker but don't underastimate that and say that it's a week engine because its really not, u can do a lot in Gamemaker.