From my experience, it’s not about what to throw, for river smallmouth, it’s always about where to throw it. It’s always about current. If you are just starting out, the best advise I can give, is to look for moving water and current breaks. For the most part, smallmouth won’t hang out in the fast water unless there is something to break the flow that they can hide behind so they don’t have swim against the current all the time. At the same time, they depend on that current to bring the food to them. During the summer, when oxygen levels get low in warm water, fast bubbling water resupplies oxygen, and the bass will often be found nearby.
So, look for areas of fast water where there are rocks or wood to disrupt the flow. Get your bait to drift with the flow as close to the slack water formed behind the rocks or wood as you can. Bass will be looking into the current for food to pass by.
If you are floating between prime sections, look for downed trees along the shoreline, shade lines, and trees that overhang the water. Also, look for water where the water is swirling or disturbed on the surface. It means there are rocks underneath and are good places for smallmouth to find underwater eddies to sit in.
Slow moving or deep water are lower percentage areas so don’t spend a lot of time fishing them. Do spend more time when you find areas like I described above.
For baits, keep it simple. Topwaters, weightless Senkos, Ned rigs, or spinners will nearly always produce as will many, many other baits. Anything you can get CLOSE and I mean VERY CLOSE to the spots smallies are laying can get bit. If you miss the target by more than a few inches, it can be the difference between zero fish and a day you will never forget.
These are the things I look for in shallow creeks and rivers. Bass don’t always follow any rules so there will be days when they won’t be where they should be and will be found where you don’t expect. Cover as much water as you can and keep going back to learn the waters you fish. Unlike lake fish, river smallies can be caught shallow all summer long. Good luck!