Do all rivers run north to south?

No, the St. Johns River in Florida runs south to north. no! rivers run from their source ie mountains to an ocean or swamp or lake. to give an example, the nile river runs from south to north and the orange river(namibia and south africa) flows from east to west...
Rivers that aren't "north of the equator running south":
Athabasca Alberta, Canada, 765 miles
Bann Northern Ireland
Bighorn Wyoming and Montana, USA, 336 miles
Cauca Colombia, 597 miles
Deschutes Oregon, USA, 250 miles
Eel Northern California, USA, 78 miles
Erne Ireland and Northern Ireland, 60 miles
Essequibo Guyana, 600 miles
Genesee New York, USA, 144 miles
Jordan Utah, USA, 45 miles
Lena Russian Federation, 2735 miles
Little Bighorn, Wyoming and Montana, USA, 80 miles
Magdalena Colombia, 1062 miles
Mojave Southern California, USA, 100 miles
Monongahela Eastern USA, 128 miles
New Virginia and West Virginia, USA, 255 miles
Niagara Lake Erie to Lake Ontario, 39 miles.
Nile Africa, 4150 miles
Ob Russian Federation, 2289 miles
Oswego New York, USA, 24 miles
Otter Creek Vermont, USA, 75 miles
Pend Oreille Washington, USA, 62 miles
Red Minnesota, North Dakota, USA (into Canada), 318 miles
Richelieu Quebec, Canada, 208 miles
Saginaw Michigan, USA, 20 miles.
Saint Johns Florida, USA, 275 miles
San Pedro Mexico (into Arizona), 142 miles
Shennandoah Virginia and West Virginia, USA, 55 miles
Wilamette Oregon, USA, 188 miles
Wallkill New Jersey, USA, length unknown
Yenisey Russian Federation, 2548 miles
Youghiogheny Eastern USA, 151 miles