ISO 27001 Internal Auditor or Lead Auditor

This depends on your career objectives:
- The ISO 27001 Internal Auditor certification recognizes people capable of ISMS against ISO 27001. This allows them to perform audits in their own organizations.
- The ISO 27001 Lead Auditor certification recognizes people who have competency on auditing an ISMS against ISO 27001 requirements and qualifies them to audit other organizations on behalf of a customer, or to start the process to become a certification auditor.

These articles will provide you a further explanation about personal certifications:
- What does ISO 27001 Lead Auditor training look like? https://advisera.com/27001academy/blog/2016/08/29/what-does-iso-27001-lead-auditor-training-look-like/
- ISO 27001 Internal Auditor training – Is it good for my career?  https://advisera.com/27001academy/blog/2016/03/29/iso-27001-internal-auditor-training-is-it-good-for-my-career/  

These materials will also help you regarding audit training:
- ISO Internal Audit: A Plain English Guide https://advisera.com/books/iso-internal-audit-plain-english-guide/
- ISO 27001:2013 Internal Auditor Course https://advisera.com/training/iso-27001-internal-auditor-course/
- ISO 27001:2013 Lead Auditor Course https://advisera.com/training/iso-27001-lead-auditor-course/