Custom fields in the Report Templates
Make sure they are marked as searchable. On your:
civicrm/admin/custom/group/field?reset=1&amp;action=browse&amp;gid=1

(assuming it's your first Custom Data set)

Check the Searchable? Column; If you toggle that to Yes - then reports that pull in custom fields will show yours at the bottom of Columns and Filters - e.g.:


The Searchable? = Yes field shows is select-able in the Report: