Building a treehouse with my 6yo and I have no idea what I'm doing

So I promised my son a treehouse last year and finally committed this weekend. I watched like 3 YouTube videos and bought wood from Home Depot. We've got a platform about 4 feet up in the oak tree in our backyard. My wife keeps yelling at me about safety but honestly it's holding. The best part is watching my kid's face when he climbs up there. Pretty sure I did the weight distribution wrong but we're gonna see how it goes. Anyone else just wing this stuff or am I the only disaster?