Based on the current weather patterns, I think that I would wait until the week before to pack. We are going the last weekend in Feb and the first full week of March, so roughly the same time. Average temps are about 80, so you would think that shorts for the day and a jacket or fleece for the evening would be sufficient, but you never know.
As for shoes, the last time we went, our kids were 1.5 and 4.5 years-old. At the start of the week, they both wore tennis shoes, but then the older one complained that her feet were sore, so we switched both of them to crocs for the rest of the week. They were both happy and the older one, who wasn't in a stroller, never complained again.