When I submit a suggested edit, a notice would say that my edit "Won't be viewable to other people until it is approved by trusted community members" (sorry if I did a quotation mistake), but it doesn't specify how much reputation is required to become a "trusted community member."
Although not stated explicitly, I think this is referenced at the access review queues privilege page. I believe you need 2,000 reputation points on this site (Meta Stack Exchange) to become a trusted community member (for approving suggested edits purposes), because it says:
Suggested edits - 2,000 reputation
That number may be different on other sites so check their access review queues privilege pages to see what applies to your site.
This is different to the trusted user privilege (20,000 on this site) so I can understand your difficulty finding it.