Be prepared to make one if you decide to run. The number of delegates from each precinct is set by the party. All voting is by secret ballot. Each party may use different rules for selecting delegates. The Republicans use the plurality method - nominees who get the most votes become the delegates.
Winners take all.
Alternates can either be those with fewer votes or be selected by separate balloting. The DFL may use either the plurality method or proportional voting - a method that gives subgroups in the caucus a share of the delegates. Use of that method is voted on at the caucus. Those who wish to form a subcaucus designate a candidate or an issue or both. There must be enough people in each group to entitle them to a delegate.