What's wrong with my pears?
It looks like the leaves are being chewed by pear slugs - here is some information about these pests - https://pnwhandbooks.org/insect/tree-fruit/pear/pear-pear-sawfly-pear-slug They are best removed by hand or using a strong spray of water. If you consider an insecticide, please ensure that you do not use anything toxic to bees or other pollinators - read the label and follow its instructions.
The pears appear to affected by pear scab. This is a fungal infection that usually overwinters in fallen leaves. Here is some information - http://hortsense.cahnrs.wsu.edu/Search/MainMenuWithFactSheet.aspx?CategoryId=3&PlantDefId=64&ProblemId=94 Try out cultural controls first. Rake up all leaves and debris and dispose. Prune to increase air circulation and sun penetration. Use drip irrigation only - no overhead watering. Fungicide application may be considered later during tree's dormant period.