Deer do love apple wood and can really cause problems. It is too late to consider pruning much now. Diseases like fire blight are already present. So on a dry day when there has been no rain prune out branches that are crossing and rubbing or any broken branches. Plan on pruning next year before leaf out. The one on the left  could be given a heading cut as described in the reference links. The tree on the right looks like a candidate for an open form and no central leader. You tube has many videos on how to prune apple trees and I find it very useful to watch 3-5 of them when I am learning something new. 

https://www.bhg.com/pruning-apple-trees-6755200#:~:text=Late%20winter%20or%20early%20spring,in%20fall%20or%20early%20winter.
https://www.starkbros.com/growing-guide/how-to-grow/fruit-trees/apple-

trees/pruninghttps://www.finegardening.com/project-guides/pruning/two-ways-to-prune-new-fruit-trees

https://yardandgarden.extension.iastate.edu/how-to/how-prune-and-train-young-apple-trees