Some yellowing of the lower leaves is often seen on nursery plants just moved into the outdoors. Those leaves developed in conditions of much less intense light. Put them in direct sun and they can't handle it so they turn yellow and eventually die. Not a problem as long as the new growth looks good, don't worry.
About watering, newly transplanted plants need to be watered often for the first week or two, but after they get established, a deep watering once a week is sufficient. Well, depends a bit on conditions of soil, temperature, humidity etc. Once a week watering is what my garden gets no matter what the weather.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-