Will I receive an email when my application officially goes under review?
you will receive an email when your file is deemed complete and sent over to the candidate evaluation review board, but that doesn't mean it will be evaluated imminently. Since you are a college applicant, your file wont be reviewed until sometime in the new year.
Only re-applicants in their first year of college are not allowed to do EA. All other college applicants that opted to do EA will be reviewed as part of EA.
From the CGA website:
. Re-applying students in their first academic year following their non-selection decision are not eligible to apply for Early Action. All other college students may apply in the Early Action period and will be reviewed using their final high school transcript. All students are required to submit transcripts from all academic institutions they have attended.