Calculating total sales from each member
I won't comment about the fact that this is a static method in what's possibly a static &quot;helper&quot; class and that it would be much prettier in a service class instance... but I just did.
The method is doing way too many things.

Thing one:
// Make a list of all users who are on the team


That's one method. But there's a twist: you not only need all users on the team, but also the teamGoal figure. I'd encapsulate that in its own class:
public class TeamGoalAndUsersResult // todo: rename this class
{
    public IEnumerable&lt;ProPit_User&gt; Users { get; private set; }
    public string Goal { get; private set; }

    public TeamGoalAndUsersResult(string goal, IEnumerable&lt;ProPit_User&gt; users)
    {
        Users = users;
        Goal = goal;
    }
}

And then you can write a method/function that will return that type:
private TeamGoalAndUsersResult GetTeamGoalAndUsers(int teamId)
{
    using (ProsPitEntities db = new ProsPitEntities())
    {
        var goal = string.Empty;
        var team = db.Teams.SingleOrDefault(x =&gt; x.teamID == teamId);
        if (team != null)
        {
            goal = Convert.ToString(team.goal);
        }

        var users = db.ProPit_User.Where(x =&gt; x.teamID == teamId).ToList();
        return new TeamGoalAndUsersResult(goal, users);
    }
}



Performance Issue:
            var lstorderTotalRep = (from o in db.Orders
                                where o.DateCompleted &gt;= dtStartDate
                                where o.DateCompleted &lt;= dtEndDate
                                where (o.Status == 1 || o.Status == 2)
                                where o.Kiosk != 0
                                where o.SalesRepID == propit_User.SalesRepID
                                orderby o.OrderTotal descending
                                select o.OrderTotal).ToList();

            foreach (var item in lstorderTotalRep)
            {
                //orderTotalRep =+ item;
                orderTotalRep += item;
            }


You're doing all the computation on the client. I'd take a wild guess and say that this is where your bottleneck is. Do you really need to select, sort and materialize all orders just to sum up OrderTotal?
var total = db.Orders.Where(o =&gt; o.DateCompleted &gt;= dtStartDate
                              &amp;&amp; o.DateCompleted &lt;= dtEndDate
                              &amp;&amp; (o.Status == 1 || o.Status == 2)
                              &amp;&amp; o.Kiosk != 0
                              &amp;&amp; o.SalesRepID == user.SalesRepID)
                     .Sum(o =&gt; o.OrderTotal);

orderTotal += total;
dtg.DailyTotal = orderTotal;
dailyTeamGoals.Add(dtg);

The above doesn't sort anything, has the same criterion and performs everything on the server side, without materializing every order in the way. Also I believe if the table has all the fields used in the WHERE, in an index (guts tell me &quot;especially DateCompleted&quot;), that would further help the server-side processing, but that's something you're probably better off finding out with a profiler.