Chicago public transportation options
It might not be quite as fast as hopping on a train, but CTA's network of buses can get you to parts of the city that are difficult to reach by rail. There are more than 100 bus routes throughout Chicago, which passengers can board at designated bus stops. Bus fare is $2.25, which can be paid with a Ventra card or with cash. If you're going to take a bus, you should probably download a transit app so that you can keep track of bus arrival times.
You can find more information on the CTA website.
If you want to choose your own route through the city, consider taking advantage of Chicago's bike-share program, Divvy. There are more than 500 stations throughout the city, stocked with bright blue bikes that you can rent and return to any other station. At kiosks located adjacent to each station, you can purchase a 30-minute rental for $3 or unlimited 3-hour rentals over the course of 24 hours for $15 (credit or debit cards are required). You'll have to supply your own helmet, but that's a small price to pay for access to Chicago's many bike paths and lanes.
You can find more information on the Divvy website.
While CTA trains will get you where you need to go within the city, if you're heading to the suburbs, you'll need to ride on the city's commuter rail system, Metra. People who live outside of Chicago but work within the city use the trains to commute, but it's easy to use Metra to get to some attractions outside city limits. In downtown Chicago, Metra trains depart from Ogilvie Transportation Center, Union Station, Millennium Station and LaSalle Street Station. Tickets can be purchased at some stations or from a conductor on the train, and fares range from $4 to $8.25, depending on how far you're riding the train. On weekends, you can purchase a $10 pass that allows unlimited rides on Saturday and Sunday.
You can find more information on the Metra website.