City car searched- Ignorant asks for support

Good day together, my partner and I would like to buy a car. We live in a city close to the center with good connections to public transport. So I have delayed the car purchase until now. But now we believe that a car could support us in our everyday life with regard to shopping, driving to the sports centre, spontaneous activities and so on. Unfortunately I am totally ignorant about cars. I’m probably the classic buyer that you can easily overhear This is why I am looking for support or advice. What I am looking for / My idea: a kind of city car. Small and relatively little fuel consumption. Budget: I disagree here. If new cars could possibly be up to 15,000€. Used so between 5,000€ and 7,000€. I basically like the Mazda 3 skyactive, BMW 1er from style. But I’m not sure if a VW Polo 1.2 or suzuki swift would not be the better choice. What about this offer? n Polo recommend or should I possibly orient myself to the other ? Thanks