The apples in your photo likely have been impacted by plum curculio. It is a weevil that lays eggs in the apple, causing the dimples. This occurs right after petal drop when the fruit is just forming. Cultural control, picking up all dropped fruits, leaves, branches, this fall, is helpful for control. In the spring you can place apple nylons or baggies (with a small hole cut for water to drain out) around the new fruit as a method to control. Chemical control is also an option. Insecticide, that notes it controls the weevil, following petal drop and twice more, every 10 - 14 days, is needed. Always follow package instructions and know there can be an impact on pollinators. Here is a link about the plum curculio.
https://extension.psu.edu/tree-fruit-insect-pest-plum-curculio

The dark areas on the trunk looks like canker. This could be from damage or disease. I would recommend contacting a local tree care company and ask for a consultation with a certified arborist. They will be able to assess the full tree and let you know what, if anything is going on and next steps, if needed. Below is a link to growing apple trees in Minnesota. It includes a calendar of what care is needed throughout the season. 
https://extension.umn.edu/fruit/growing-apples