I suggest getting a subscription to ACloudGuru or Cloud Academy. I'm more partial to Cloud Academy these days. They're both about $50 a month.
Then go through the Certified Cloud Practitioner course. That will give you the very basics.
Once you're done with the CCP, you can move to the Solutions Architect Associate course. You don't have to get the certs (although they are useful). But the courses will give you a good understanding of AWS.
Just to be clear, that's about 50 hours of content. But I suggest being over-prepared rather than under-prepared.
acloudguru.com
cloudacademy.com
