Elevated bun, elevated k+ , elevated chloride, normal creatinine, and decreased co2. could this indicate kidney failure?

Probably not: I need more information in order to optimally answer your question. However, at a glance, the best indicator of kidney function is creatinine clearance. BUN can be elevated from other processes. I would need to look at the lab report to confirm your impressions. You are too young to have CKD. You should review the labs with the doctor who ordered them.