To be accepted and successful with Google AdSense, you need pages with unique content that’s relevant to your visitors and provides a great user experience. Before you apply to AdSense, Google recommends you check out the tips below to make sure your pages are in good shape:

You should take care when using external resources such as articles on other sites or embedded videos. It’s really important that you contribute your own original content, whether it’s specialist knowledge, improvement ideas, reviews or your personal thoughts. As stated in the Google content policies, Google ads may not be placed on sites with scraped or copyrighted content.

You can only apply directly for Google Adsense if you are 18 years and above. However, if you are not yet 18, you may have a parent or guardian sign up for AdSense using their own Google Account. If their AdSense account is approved, Google will make all payments to the adult responsible for the site.

"All publishers are required to adhere to Google Adsense policies. If you fail to comply with these policies without permission from Google, it reserves the right to disable ad serving to your site and/or disable your AdSense account at any time. If your account is disabled, you will not be eligible for further participation in the AdSense program."

Hope you find this helpful https://www.getadsense.net/how-to-get-adsense-account-approved/