@user_zero, Thanks for posting in Q&A.
Based on my experience, currently, there is no such way in Intune to check a device's compliance-related settings before adding it to a compliance policy. If you want to know whether a device is compliant with certain compliance policies, you have to either check at the device end or go through a policy analysis after assigning the device a compliance policy in order to come up with the device's setting status. After that you can correct the non-compliant settings on device.
You can refer to the following links to set up compliance policies and monitor the status of the device after applying the policies
https://learn.microsoft.com/en-us/mem/intune/protect/device-compliance-get-started
https://learn.microsoft.com/en-us/mem/intune/protect/compliance-policy-monitor
As for device enrollment, here are some methods mentioned in the following link.
Hope above information can be helpful.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.