Smart Roadster for 1.85m and 145kg?

As the title already says, I want to get it straight to the point. I am 17 and want to get my first car close soon. To study I probably need something small, moderate in the maintenance for the city. Therefore, the numbers of the smarts let me ponder whether it will become my future. Hard consumption, virtually no tax, unconventional, exotic design. Eigtl. exactly mine. But since I don’t understand anything about cars and have not yet sat in a real one , I would like to know from you: What kind of mileage can you expect? And do I even fit in there? (1,85m/145kg) in various forums it was called up to 2m you should probably climb but in sitting there do not have any problems. I thank you for your help and am happy to be open for other suggestions!!