I'm sure everyone has! What exactly are you supposed to be finding out? Rivers flow as rain water seeks its lowest level. On the eastern seaboard, rain falling on the east side of the Appalachians runs into the Atlantic. On the west side of the Appalachians, the rainfall drains into the Mississippi. On the west coast, the Rockies perform the same function, but to different outlets such as the Pacific. Rainfall drains into small streams called tributaries which in turn flow into rivers. As the water flows downhill, it picks up loose materials from the land such as earth, rocks and even pesticides and feces from animals. As the water flows, some of this settles out and creates sandbars or gravel bars. Unfortunately, pesticides and feces don't really settle out. Many major rivers are polluted from this as well as acid rainfall and waste from industrial plants (which is supposedly regulated by the government). Rivers can be narrow or broad, some several miles in width. Most rivers do not have clean water because of runoff and pollution. Rivers gives us our drinking water, power industry, provide transportation, supply wildlife with water, and people with food. If pollution is not controlled, people and animals can be sickened by the water and the food sources living within it. I hope some of this answered your question since it was pretty vague.
I have lost count of the number of rivers I have seen. Presently, the city I live in has two rivers, Mula and Mutha flowing through it, in which merge into a single river within the city limits. In the past I have lived in cities that were located on Banks of two greatest rivers of India, Ganges (called Ganga locally) and Yamuna.
The first river I distinctly remember having seen is Verupa river, which flows along the town of Cuttak in Orissa state of India. I saw this river about 59 years back when I was 5 years old. And I have crossed this river several times riding in a jeep that drove along a ford built on this river.
I have close association with the river Ganges also. I lived in Kanpur situated along the bank of this river for two years, and grew up there from age 9 to 11. While living in Kanpur, I bathed in Ganges several times.