A good tip to figure out central park is to look up and see where the slides are.They are located at the front of Central Park.I had same issue at first.lol
Next time you're in Halifax, Starbucks is in the Superstore grocery store a few minutes walk from the pier.Its just one that says Atlantic Canada,so you can get in in NS,NB,PEI,and NFLD.
Speaking from experience......you won't stay completely dry. We had one last December and it rained hard for a couple hours and got wet,not soaked but wet. Also depends which way the rain is falling as well. Staying in on the couch would be where you would keep the driest. I moved out under the umbrella as I was getting wet sitting in the chair.