Changing wording across NavBar tabs


I hope all you guys are doing great.

Sorta seeking to obtain your attention in order to get some guidance on how to replace words from NavBar tabs.

I have tried some many ways without success.

Also, sorta same thing is going on with replacing the image on header. I couldn't get any information on how to do it properly.

Any advise will be very much appreciatted.

Have a great one,