How to create template?

To the best of my knowledge, you just add the template file in the template folder in the Creo Common sub-folder.

...\Creo 2.0\Common Files\M030\templates\

This is the default folder where Creo looks for these files. But you can change this folder with config.pro which is highly recommended so you don't loose your customization when you update the S/W. See "start_model_dir" in config.pro

Once you move the new template files into the appropriate folder, you need to reboot Creo to see them. I just moved a part called my_start_part_mm.prt (remove the numeric extension) to the templates folder and after rebooting Creo, it showed up when I started a new part.

..and if you mean "formats" for drawings, these are in a different location.

You create formats by starting a new format or copying an existing one and modifying it.

In Creo, start a new part type "format" (.frm) (file/new/format). There is a format folder in the Creo sub-folders as well where these need to be stored by default.

Remember that intelligent formats use tables with "relations" as variables. Only table variables in formats will accept the part and assembly relations automatically.