I've got two but I'm unsure which was first, I think they were around between 2, 3 years old. I don't really have much context or as to why I have them but they are pretty clear.
The first is standing in the garden of our house, looking up at the stone wall where our neighbour was leaning on and talking to my mum who was looking down and along at me as if they were conversing about me, making gestures as I walked towards them from near the back door. The neighbour had some sort of sweet for me which she handed over the wall.
The second I remember is pooping my nappy while I was in a small room at the back of the house where the door was and which had a couple of wicker chairs and books among other things in it. I remember walking over near one of the chairs, bending forwards and pushing a big firm poop out before walking back out of the room, almost as if I'd decided that the side of the wicker chair was the perfect place to go to the toilet and went specifically there for that, lol
After that you get into nursery / preschool memories which have a bit more context. But these are my competing earliest ones.