The majority of eligible channels hear back in less than 30 days. Be sure to look out for an email or Studio notification from us! In the meantime, you can check out this help resource for more general info about the review process: https://yt.be/help/YPP-review
This means our review team hasn't come to a clear decision during the 1st review, which usually happens if your content is close to not meeting our policies. You can check our YPP Policies here & use this time to make updates: https://yt.be/help/YPP-review