how to grow a dwarf cherry as a fan

[divvy]

Hi, I have a stella cherry on colt stock and want to grow it as a fan up the fence. I have planted it in an 18" pot, tilted toward the fence and put wires up ready for the canes. The problem is that looking on the RHS site, they say to choose 2 laterals that are 12" above the ground as your starting point. My tree is the right shape with laterals and fan shape but they start at 4 ft above the ground. Now, should I wait for the feathers that are growing down the trunk for get longer as laterals and then cut the top off the tree. As you can see , I don't know what I'm doing and all advice would be most welcome.I have also planted 2 dwarf apples, one Discovery and one Egremont Russett and a dwarf victoria plum.All look to be doing well , but again any advice would be welcome. Thank you.

[BarleySugar]

Would it be possible to plant it in the ground? According to the grower I bought mine from you need 2 6ft high fence panels to train it against, and an 18" pot doesn't sound very big for a tree that size. Also that would lower your branches to be trained.