AWS was the first to sell it, but Google had something that could be called cloud computing (Borg) before that.
What do you think AWS decided to sell? Both companies had a significant interest in making infrastructure easy to create and scale.
AWS had a cleaner host-guest abstraction (the VM) that makes it easier to reason about security, and likely had a much bigger gap between their own usage peaks and troughs.
Yep. Google offered app engine which was good for fairly stateless simple apps in an old limited version of python, like a photo gallery or email client. For anything else is waa dismal. Amazon offered VMs. Useful stuff for a lot more platforms.