Hi @krishnakanth.k:
According the 1. point:
I assume that you published the Test Cases to Orchestrator but did not create a process out of it.
As you would do with RPAs, you initially after publishing have to go to the process section on Orchestrator, select the published Testing package and create a Process out of it (Package + Environment)
As soon as you have done this, your Project should show up in the Test Set wizard.
Every proceeding publishing to Orchestrator of the same project will automatically be available, as long as you do not change the Major.Minor version of the package.
About the 2nd issue with publishing libraries:
No idea what the issue is here, but it might be helpful to share the project and the call stack of the error message