i havent used Vulkan yet as i am busy with my current project, my question is, how easy or how hard it is to adapt old graphics/shader techniques such as shaders to vulkan,

what I mean are things like deferred rendering like lighting, shadow mapping, effects that uses other/extra textures for mapping, deferred rendering, etc.

i have searched for vulkan tutorials yet and there are no lessons for lighting and shadow yet, well its my fault too, havent tried Vulkan yet.

can you guys give me idea on how to translate these techniques to Vulkan?

Thank you in advance!

Vulkan uses the same GLSL for now than OpenGL, you can expect to keep using shaders without much need for changes.

Techniques like deferred rendering are not tied to an API, you can implement them in the same way you already did.

Tutorials assume you have experience with other APIs, so thy focus only an basic API usage and it's concepts.

There's however nice source code with implementations of many techniques: https://github.com/SaschaWillems/Vulkan

Probably it will take more time to render your first triangle than to go from that to deferred lighting.

It's really the basics you want to learn. Techniques you already now just remain the same ideas and you will only try to make them more efficient.