Photoshopの新規ドキュメントにあるテンプレート（8種類）のフォトコラージュレイアウトの使い方について

There are so many ways to make Collage templates. There are many tutorial on the Web for making Photo collages. There may be some in your language. The browser translated your append to include  (8 types), template 5, and template 8, but no information about where these template can be found  or what the 8 types are.  

Photoshop includes a feature  Data Driven Graphics for populating Templates you create with defined variable layers with your Text and Images. There are Scripts and Actions that you can downloaded from the web for creating Photo collages. Some include Templates.  

You may want to look are my my Photo collage toolkit  I made for Photoshop.

However before you try making Collages in Photoshop you need to know basic Photoshop editing features.   Collages are quite easy to create in Photoshop.  There are many types of Collages and montages and countless number of ways to make them.   You need to understand and able to use Photoshop  Layers, layer mask, and blending well. 

Layers are scaled by transforming them and are mask to shape.   Photoshop has a 8000 layer limit you can have hundreds if images in a collage.

Smart Object layers have advantages and disadvantages in templates.  I tend not to use use Replace Object content  because the replacement need to be the same size are resolution as the original smart object.    Smart Object Layers in templates work well for  Picture packages where several smart object layers share a common smart object.  They are also useful if you need to add rotation and perspective to the image  appearance in the collage.