Deploying applications and microservices

Mostly not the tipical question.

I’m looking for information on how to deploy application more commonly microservices.
I run my own servers and have my own k8s cluster and docker-compose cluster.

All my online courses explain how to develop a program, but never explain how to deploy them in a production environment.
On most of my apps I do have a ci/cd pipeline with only building stages and testing stages.

I would like to learn how to deploy to production with enviromental variables for sensitive information and connectionstring, but also how to deploy microservices as the general idea is to only redeploy the container you have changed but not every container.
I’m a .net developer so c# is my main language.

If anyone has some information, online courses links that would be very gratefull as I like somone that can explain me this in detail?

I don’t find the right information on google so I probably type the worng thing in google.