How do i rename the Project Workflow status names

[Volodymyr_Krupach]

Probably you mean statuses. The simplest and most intuitive way is to go to workflow editing, diagram mode and double click on the Status. Please check: https://confluence.atlassian.com/adminjiraserver072/working-with-workflows-828787890.html

Or just locate Statuses under Administration -> Issues.

[G Varma]

How do I rename the Project Workflow stage gate names ?

[Nic Brough {Adaptavist}]

If by "stage gate" you really mean "transition", then it's the same answer - go into the workflow, edit it, find the transition and rename it.  See the doc Volodymyr already pointed you to.