Advice about where to live in Oahu?

My husband passed last year and now it is just me and my 9 yr old son. My mother and sister passed the year before we have nothing holding us to Tulsa, OK anymore and would like to move to Oahu in the next year. I work in the medical field would like to be somewhat near a hospital or easy bus route to hospital. Nice elementary school for my son. We would love to be in a community but near the water. I have been looking in at Kailua and Ala Moana. What is the best side of the island to live? Would like sunny and drier. I have heard one side is rainy is that true? Also what is leeward side ? I do not understand that. My son and I have had a rough go of it the last 2 years and we are looking forward to slower paced life in a community we can love. Any advice would be very appreciated.