Security is an essential part of software construction. It may become harder to retrofit security in a developed software. There are fantastic resources to learn software security from. Please find list of resources I stumbled upon:
Introduction to Software Security by Elisa Heymann and Barton P. Miller
https://research.cs.wisc.edu/mist/SoftwareSecurityCourse/
A second one is Software Security On-line Course, https://mhicks.me/software_security_course/
A great read for a book, Software Security: Principles, Policies, and Protection (SS3P, by Mathias Payer), https://nebelwelt.net/SS3P/
For practical perspectives we can choose to follow OWASP Development Guide from
Professional certification related to software security is the ISC2 Certified Secure Software Lifecycle Professional (CSSLP)
https://www.isc2.org/certifications/csslp
