AINP will evaluate and verify your documents (work letters, IELTS, education documents etc) themselves first. They do contact your employer via email so make sure to remind your work references to keep an eye out for AINP's email. If AINP is satisfied with the verification of your documents, they will/may nominate you for PNP under AINP which you receive as a letter in your EE profile. You'll have 30 days to accept (or reject) the nomination. Once you accept the nomination, 600 points will be added to your CRS score and you'll get an ITA from IRCC in the first all program or PNP draw. The rest is similar; IRCC will send you a document checklist that you'll need to provide. And they'll also do their own verification.
For EE details on eligibility, medicals, info sharing and security, just keep reading these forums. To actually find out what's happening with your application behind the curtains, you need to order GCMS notes:
https://www.getgcms.com/blog/gcms-notes-look-like-order/