First of all welcome.
Not being familiar with fishing from a kayak I would guess you are generally casting using a horizontal presentation casting your baits. I am usually using a vertical presentation by tight lining or dipping around standing timber or brushpiles.
I would be starting off say early in the day working around the bridge pillars on the Little Bull and the four corners on the riprap around the bridge. On the corners I would be bouncing the jigs on the bottom in the rocks at various depths. On the pillars I would be flipping jigs out to slowly pendulum down next to the concrete pillars. Trying differing jig weights to vary the fall rate. For me Hillsdale has always been notorious for the bite to shut down later in the mornings.
If the bridge area doesn't work out I would be out over the channel edges working the standing timber. If that didn't work I would try and tight line on the flats off of the channels trying to find a depth they are in and biting.
I'm using electronics to locate the fish and channel breaks or edges looking for marks to give me confidence to work areas.
Hillsdale is my home lake but all I can say is I am struggling a lot of the times I'm out there.
Anyhow good luck out there.