Can't change homepage

Hi there!

Using maOSMojave. Two days ago opened Safari, clicked "create a new tab" and it opened Google. Again and again. Went to Safari Preferences >General and saw that "new windows open with" is not active, but it says "homepage". My Homepage must be Favorites, but it was Google and I also couldn't change it.

Then I noticed that even using Google search, it brings me to Yahoo results. I went to Extensions and found suspicious extension, uninstalled it, now my Google shows me results in Google...but my not active homepage changed for Apple web-site.

So as far as I understood, I just need to change homepage. But I can't. I tried to find answers on the Internet, but didn't find situation when it was not active

Please, who knows what to do?

Thank you!