If I made reservations for the canoe at 1pm do I still need to get to the park early to get in before it reaches full capacity ? How does parking work ?

If you have reservation you should be good to just check in, but to find parking maybe go early. We parked off the side of the road of this place.

No

Thats just for the rental...

Your good you have a reservation.

The river won't fill up. Kings Landing is just a rental place off the river. It's not a park. Parking can be tricky because it's along the road. We rented at 11am and found close parking.