Don't feed until your water temperatures are above 50 degrees & likely to remain that way. Start with a 'spring/fall' or 'all season' food, and it's not a bad idea to start out with a few days of plain Cheerios at first. (they're great all around snacks for the fish even in summer) You can switch to a Summer food when the water temps are constantly above 60 degrees, I believe (I stick to All Season, so you'd have to confirm that with instructions on the bag's label)
Fish aren't as hungry in cooler water, so you probably won't need to feed but once a day for a minute or two at first, then more as the water/weather gets consistently warm.
I actually don't even have to look at my pond thermometer to know the temperature - my fish do NOT beg until it hits 50 degrees. They'll swim around & look at me, but the actual begging doesn't start until then!