Piestewa Peak might be one of my favorite hikes.
It is the perfect any day of the week hike but you note that Saturday/Sundays will get packed. Good luck finding parking. Not impossible but can be somewhat challenging for sure.
At the peak there will be a lot of people but there is plenty of areas to sit and hang out and take good picture or just enjoy the view.
Don't let this hike scare you, there are many of ages making this hike. You can make it a bit more challenging by picking up your paste if you feel that the hiking isn't challenging enough.
Hike responsibly, drink water, pick up your trash and share a smile with those that walk by. More importantly, enjoy yourself.