Where should I change name

It depends on what you mean by rename. Rename what? Files? Text outputted to the screen in an html view? Variable names used in code?

There is no single place where names of things are defined. It could be all throughout the code.

There is nothing named "dashboard" that comes with a stock Laravel install, so you'll have to be more specific about your individual application.

I'm assuming you didn't code this project, since you don't know where these things are defined?

https://nova.laravel.com/docs/2.0/customization/dashboards.html#customizing-dashboards

I don't understand what you mean:

How to rename resources

I suppose you can redefine if needed, or rename a model:

https://nova.laravel.com/docs/2.0/resources/#defining-resources