I Think I Have A Kidney Issue, I Got A

I think i have a kidney issue, I got a report that reads eGFR Non-AFR. American 55L I took another blook sample in and it went to 51L my Calcium was at 9.3 and uric acid at 5.3 I have no Idea what that means but I got a call from the Dr. office to come and see them about my test results. What do all these numbers mean