Dragging speeds are going to vary based on conditions.
This time of the year though, I would never be going faster than .7mph downstream and .5mph upstream. (take those speeds with a grain of salt, 95% of the time, I’m not going anywhere near that fast)
I rarely move at or above .3mph on the upstream runs.
When you first start, concentrate on knowing your jig is close to the bottom. You do this by letting your rod tip drop back and watching your line. If it goes slack, your within range of the bottom. If you are constantly banging bottom, your either moving to slow, have to heavy a jig on or to much line out.
Also when first starting, don’t start by dragging over deep water. Get comfortable with depths at or less than 15’deep, then give the deeper water a try. Eight feet of water is not to shallow to drag in. Neither is six feet or even the occasional four foot depth. Especially after dark.