No, I haven't played anything by Amanita Studios, but I'm efinitely going to now! Thank you for the tip. :)
I too have limited coding/dev experience, but I find Unity quite approachable. I'd only done two tiny games by myself previously--a crummy platformer demo, and a weird little art game. It's just a question of figuring out exactly what you want to do, and googling for tricks and tutorials on how to do it. You'll learn the software as you go along.
My main advice is to keep the scale of you first game as small as possible. Seriously small. Most likely it'll grow out of hand later anyways. Storyseeker was originally supposed to be a 2 week project to test out how to make a game that has no other mechanic besides walking around. 6 months and innumerable features, characters, scripts, and entire new zones later, here we are...
Please, if you ever need any help or want me to have a look at something you're making, contact me on twitter @qwertyprophecy. Good luck!