I'm self taught, so just learning from practice and reading documentation was my best bet. Construct 3 is easy for beginners but a little on the expensive side, and Unity is more complicated but 10x more powerful and free. Audacity is good for sound, if you can't make your own stuff than I suggest you use stock sounds. And for visuals if you are doing 3D then model with Blender, it's easy and there are literally tutorials for everything in it. If 2D then use gimp or something like that to make some stuff. I use IbisPaintX because it is just easy and I can do crap on my phone which is super efficient, along with a payed subscription to Pixlr, cheap and also efficient.
Hope this helped!