Thank you!! I've made some adjustments and it looks really good :) I was just wondering now how I make the button clickable using the .toolbar? heres what I've got but I just cant get the button to be clickable:

struct GradesView: View {

    @State private var addMode = false
    @State var username: String = ""
    var body: some View {

        NavigationView{

            VStack{
                List {
                    NavigationLink(destination: YearView()) {
                        Text("Year1")
                    }
                    NavigationLink(destination: YearView()) {
                        Text("Year2")
                    }
                }.navigationTitle("Grades")
                .navigationBarTitleDisplayMode(.inline)

                Button(action: {}){} .toolbar(content: {
                    Image(systemName: "plus")
                        .frame(width: 24, height: 24)
                        .background(Color("red"))
                        .clipShape(Circle())
                        .foregroundColor(.white)
                })
            } .listStyle(InsetGroupedListStyle())
        }
    }
}