plenty of fishermen out today, you could ask any of them for specific spots.

Pretty much everything worth visiting is closed on Sunday in Cache Valley. There are lots of great hikes up Logan Canyon, I personally like Jardine Juniper and the Crimson Trail. But those are probably too long if you are already driving so far. You could do the Wind Caves or there is the Pinyon Pine trail near the summit before you drop down into Bear Lake.

I believe Center Street Grill is open today at Center and Main in Logan. Very good burgers and fries.