When a candidate applies, they'll be directed to the 'Intake' section on your home page. For more on managing your intake, navigate here: Managing Intake
From there, once you approve an applicant, how do I know where they'll go?
You'll have control, after approving, over which stage those candidates will enter in the job you've approved them for. The act of 'Approving' is not by any means a final decision. This simply means, I have seen enough just from scanning the resume not to reject them immediately but I may always pass on them later.
Within your Recruiting Workflow (see below) you'll be able to control which stage an approved candidate is moved to. To do this, navigate to Settings>>Workflows>>Recruiting Workflows and set the stage of your choice to 'Type' (#5 below) = NEW. Whichever stage carries a Type=New designation will be the initial landing spot for those applicants. Additionally, if you're running a search and adding contact to a job from search, those contacts will follow the similar logic that applies to your approved applicants.