I can't find template for a single door only double door

A door is inserted and the style is changed as shown on this video recording https://www.youtube.com/watch?v=d1JNGUxYYBA

Before inserting doors, you first need to use the Style Manager to define door styles.

The Door tool can be used to insert doors into walls, but you need to first define door styles.

In the Style Manager, there is one style, "Standard," listed under "Door styles." A preview showing a previous of the door style is on the lowest pane.

You can change the "Standard" style, but if you want to preserve this style, make sure "Standard" is highlighted and click Create New Style.

Assign a name. This creates a new style which is a copy of "Standard."

Open Design, where you can specify the door type (single, double, pocket, etc.) and shape (rectangular, arch, half-round, etc.). 

These are the standard door types available in the Design category of the Style Manager.

     

Source: TurboCAD