I recommend you watch this video for launching an AWS EC2 instance from 25:45 minutes, and fortunately, this video covers the basics of Cloud Computing so, if you are a beginner in cloud computing this video encapsulates all the concepts you need to get started with cloud computing, like what is cloud computing, various deployment, and service models with detailed explanation:
To become proficient in cloud computing using AWS, enroll in the AWS Certification Training course
If you wish to prepare for a Cloud Engineer profile interview, then, do check out the AWS Interview Questions list.