Most channels are reviewed in about a month. We evaluate each application manually so it may take a bit of time. Here’s more about the review process: https://yt.be/help/YPP-review . Hope you hear back soon!
Try checking your spam/junk folder in your email or you can also check Creator Studio for the reason you were disapproved. About reapplying, you would need to enable monetization in your "Status and features" page once you become eligible. Hope this helps clarify!