If I were the mayor of a big city, the first thing I would do would be to build bike lanes all over the city. Because the places where people can ride bicycles in big cities are limited and they cannot do sports due to their intense work tempo. I would try to make it easier for them to commute by bike to work. In this way, they would both go to work and do sports.
Secondly, I would make eating, drinking and sheltering areas for animals. Because we have taken away the habitats of animals. So we destroyed their natural environment. In summer or winter, animals need shelter and have difficulty finding food.
Thirdly, I would give more importance to walking paths, sports fields and areas where people can spend time with their families. People need relief sometimes, and as mayor I would try to provide that.
Finally, I would strengthen public transport. Since public transport is insufficient, people travel more with their private vehicles, which causes a lot of traffic and air pollution. I would produce projects to prevent this.