Help: change navigation bar site name

Hi,

Very nee to this, using the Nisarg theme. In the top left of my page, in the navigation bar is displays my site name and when it is clicked links to my homepage.

Is there a way to change this? Initally just change the text but I have a logo developed I want to put there eventually?

I presume this change needs to happen in the editor? Theme Header.php?

Any advice is much appreciated.

Thanks!