Talk to Nephrologist on Single Kidney Creatinine Improvement

I lost one of my kidney due to birth defect upj obstruction, got to know in 30’s in regular kub US. I other kidney doing well but it’s creatinine is 1.3 mg/dl and eGFR > 60 other bloodwork like bun, electrolytes in range. Is my creatinine is normal for single functional kidney? I did my reports with agha khan karachi so its normal range is 0.7-1.3. How can I improve it? Which things need to avoid? No markers for kidney damage in remaining kidney like protein in urine etc. Am I CKD patient? Because my nephrologist not classified it yet just advice me to limit salt and red meat in take but I am totally avoiding red meat and all the junk food since diagnosed