I've lived in the area almost my whole life, and I can tell you that hiking is the best thing to do this time of year
South Mountain, White Tanks, Thunderbird, Camelback, and Popago Park are all nice depending on which are of the Valley you want to visit. But remember that temperatures can reach well into the triple digits for a good chunk of the year, so hiking isn't an activity you can do year round in you do end up living here (unless you go super early in the morning). I've also been to a place called Butterfly Wonderland a couple times and think it's a fairly unique and fun thing to do while you're here, but going one time is enough. If anyone else has questions about the Phoenix area just let me know!