After creating our shop and being ready to launch with some facebook ads, we realised that even before creating an add we have been restricted from advertising. My questions are two:
Hope this resource will help you https://www.facebook.com/business/help/1095661473946872?id=180505742745347
1) Facebook does not require business verification until and unless the account is suspended or restricted from advertising.
If you've been restricted from advertising, then probably the reason for that is you must have violated any of Facebook's policies unintentionally.
You can check these policies by clicking on this link below to see if there are products on your website that violates the policies.
2) Business verification is not mandatory to start using Facebook ads. You can continue running the ads. Although I would suggest verifying the business to avoid any delays in the future if a problem occurs.