Just received an apple tree which I want to train as a cordon. However, it is about 5 ft long and there are lots of branches up the length of the tree. Do I just cut all these back to leave just the central stem?

I also received a peach tree which I want to train as a fan. This is also about 5 feet long with side branches all the way up as well . The lowest 2 branches are on opposite sides at about the right height, but thy are weak looking. Should I still prune just above these 2 branches?

Incidentally, I also got a cherry tree, but I dont have any worries with this.