New bike rear tire

I just bought my first bike today and I got it home and looking it over and I didn’t know if the rear tire should be replaced or not right away. Again I have never owned a bike only a dirt bike with the knobs on the tires so I know what wear looks like on those but not a street bike. The owner I bought it from said that I could probably get 1-2 months more of riding in it, I am just questioning if I should start to learn on a street bike with this much wear down the middle.