I played around with the lidR package a bit today. It is kind of fun to play with.https://jean-romain.github.io/lidRbook/index.html
My first experiment was to test mapping individual trees on the Robinson Gym map. It worked, sort of. I ended up mapping a bunch of things that weren't trees as trees. Like individual cars in the parking lot showed up as trees. It did a good job of mapping all of the trees, too.