Hi Avery.  We hope the following sites will help you with your school project.

How to select evergreens for a MN landscape

 https://extension.umn.edu/trees-and-shrubs/choosing-evergreens-your-landscape

The following site has a list of diseases of coniferous trees. http://apps.extension.umn.edu/garden/diagnose/plant/evergreen/

Conifers are planted in the urban forest because most conifers retain their leaves all year long. They make excellent choices for wind-screening projects. Evergreen conifers provide both winter and summer energy conservation benefits. https://forestrynews.blogs.govdelivery.com/2017/01/13/conifers-provide-urban-forests-many-benefits/

A brief history on using evergreens as Christmas trees and what they symbolized.

https://www.canr.msu.edu/news/how_did_evergreen_trees_become_a_symbol_for_christmas

Holly is the common name for the genus Ilex which has more than 800 species, including both evergreen and deciduous leaved species. Holly plants are dioecious, meaning both male and female plants are needed to ensure fruit production. Only the female produces fruit. It is important to have male and female plants that are closely related and flower at the same time.

https://extension.illinois.edu/news-releases/growing-holly

Rhododendrons are upright, spring-blooming shrubs. They have dark green leaves that stay attached to the plant through winter when they turn a darker green to bronze color. They require acid soil.

https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/azalea/leaveswilted.html

Ostrya virginiana (Ironwood) is a common understory tree throughout Minnesota's upland deciduous forest. Highly shade tolerant, it is slow growing in understories where it rarely grows into the canopy. Its branches are often broadly horizontal and retained fairly close to the ground.https://www.dnr.state.mn.us/trees/ironwood.html