"There is now a spot from a bike path that you can see in our yard ..." What does this mean? What is a 'spot from a bike path"? If you're talking about what can be seen under the fence, first tell us what it is. It's too far away in the picture for us to tell. And why does that need 15' tall evergreens?

Insofar as overall landscaping advice, you first need to create a PLAN on paper. Or hire a professional. It's essential to do before landscape work in order to avoid wasting time and money.

From the outside of the yard, when someone is walking down the bike path, they can see in our backyard over the fence. I need to block that vantage point somehow. I guess with tall evergreens.

No idea where you are but a large evergreen shrub like an evergreen Viburnum would work.

Sorry, I didn’t post that. I’m new to gardening and didn‘t think of that. We are in Maryland and lots of clay haha. I think the zone number is between 6-7.

You have a nice big yard. The first thing is to decide how you and your family and guests will be using it. Do you want cookouts, a garden, soccer practice, or a quiet retreat? Plan your activities and the landscaping plan will evolve from that. You might find you need a cute garden shed and that area would solve your privacy issues. The big mistake is random planting of shrubs and trees before you have a plan. It’s like buying a shirt you don’t really like but p, having spent money on it, you compound the problem with a sweater that matches, but itches, and pants the right color, but baggy! There is never complete “privacy” especially in this age of satellites and drones. Make your plan to make your space beautiful and comfortable for your family and place trees and shrubs to enhance your lifestyle. Plopping down five or six $50 shrubs won’t make your view of your yard beautiful. Visit local public gardens to see how they solve the problem, talking to their gardeners who live to be helpful. Longwood gardens springs to mind and I found several others.

Privacy is overrated IMO if you plant hedge that is 15’ tall you will never be able to see out either which to me would be crazy. Once you sit down and have a plan you could make that area for a different use . I guess I would like to know what you are planning to use the yard for. If you are planning a swimming pool then that is different from just the kids kicking a ball.. The best start is to go to your local garden center and see if they have on staff a person familiar with plants that do well in your area and specifically shrubs to start with. That is a huge yard so needs real planning. It might not all get done in one season either depending on the budget.

A quick solution would be to plant a few tall ornamental grasses, like a miscanthus variety. They are cheap, grow very fast and if you get the right kind would grow that tall. Then, next year when you have a real garden plan in mind, the grasses could be divided or moved or whatever.

There must be any number of various hedge plants that can fill the bill. Start by looking around where you live and see what plants in that category appeal to you. It's easy to get them identified on this forum of the plant ID forum.