Since your location says Minnesota, I am assuming you are coming from the north. The last couple miles into Memphis Central Station have a few blocks along the riverfront. The river is on your right side when going south. The south end of the Main Street heritage streetcar line is literally right outside the door on Main Street. There is a small and very nice railroad related museum just inside the door from Main Street. Across the street from the station is the long-standing Arcade restaurant. Nice basic good food, not special, but nice and is handy. The streetcar is a nice way to go up and down main street. $1.00 fare, $2.00 day pass. I think you can get the pass directly from the operator. Just ask. These are rebuilds of the original cars, mostly from Melbourne, (yes, the one in Australia), and are in nice condition. There is in place a loop line track that uses what was the ICRR southbound main track along the river, but this line is currently not in service, so what you have is a line up and down Main Street from Central Station to a north terminal just north of the Convention Center, also near the Pyramid. (The former northbound main track is still in railroad service, used as a single track main by Amtrak, and the occasional CN freight.) On the riverside of the riverside loop track is a pedestrian walkway on what was previously a third track along the riverfront.
Suggest that if you can work it in take a sightseeing cruise on the river. Info can be found on memphisriverboats.net. When I tried to copy it in, it came up as:
Sightseeing Cruise | Memphis Riverboats The afternoon cruise is 90 minutes, starting at 2:30pm and costs $25.00, or $21.00 if senior citizen, youth, etc. It runs down the river a ways, and then up the river a ways, going under the river bridges, and you will usually see a tow or two. The person giving the spiel is interesting, and mostly, but not completely factual. The actual river current is not really that fast, it is just that the volume of flow is massive. To get to the boat, get off the streetcar at the stop nearest Beale Street, walk down toward the river, going under the railroad just before Riverside Drive, cross Riverside Drive and walk south along the top of the landing area until you see the point to access the boat.
If you are really into heavy duty walking, the northernmost of the three closely parallel bridges across the river has a pedestrian/bike walkway on what was the north side roadway of the bridge as originally built in 1916. This bridge is the second bridge built across the river, is a double track railroad bridge, now Union Pacific, with roadways on both sides hanging outside the truss. No road usage for many years now. The middle of these three bridges was the first bridge over the lower river, opened in 1892, as a single track railroad bridge, with the deck originally planked level with top of rails so it could be used by wagons between trains. This was the southern most bridge across the Mississippi River until 1930 when the Vicksburg bridge opened. It is currently used by BNSF.