Looking to fix some complicated wordpress errors at affordable rate for my website

I want someone who can fix all sought of issues my website facing and maintain it. Website undergoing terrible wordpress unexpected issue. like registration not working , unable to add samples with figures from my admin, testimonial page comments are not able to approve, delete and depublish, It is working fine before from my phpcore website .All happened after it is being converted to wordpress... All pages should be SEO friendly. Content should be able to add from admin . like that many issues which i cant point out here and there