Sharepoint Access Management Expert for Permissions Configuration

We are seeking a skilled SharePoint expert to assist with configuring and managing access levels within our existing SharePoint environment. The primary task involves reviewing current permissions, granting new access to users, and establishing appropriate security levels to ensure data integrity and user access control. The ideal freelancer will have a deep understanding of SharePoint's security model and best practices for permission management. This is a one-time project focused on optimizing our SharePoint access structure. SharePoint Sites/Pages were already created.