Just go for PCNSE. PCNSE is a advance level certification. PCNSA is and entry level certification.
The PCNSA certification validates the knowledge and skills required for network security administrators responsible for managing and operating Palo Alto Networks Next-Generation Firewalls.
The PCNSE certification validates the knowledge and skills required for network security engineers that design, deploy, and troubleshoot Palo Alto Networks Next-Generation Firewalls.