First you need to decide whether you want to be in network security, application security, cloud security etc.
You can study for a handful of certifications and then decide if you want to take the exams or not. For example pick up CompTIA Security+, CompTIA Cybersecurity Analyst, Certified Cloud Security Professional.
Once you have the know how and are able to talk that language, start looking for job postings and see what they require and if you have connect.
To be able to transition into a new domain with 12+ years of experience, the easier path would be to apply within your organization as you would be able to approach people directly and politely ask them to guide you.
I have seen someone with absolutely minimal knowledge of security become a security head or a large company coz he was really good with handling people and getting work done, plus he was well connected.
