How to render different templates in layout typo3 9?

I have these template structure

Resources/private/Layouts/default.html

Resources/private/Partials/Footer.html
Resources/private/Partials/Header.html
Resources/private/Partials/Search.html

Resources/private/Templates/Default.html

I want to render 1column structure, 2column structure, Default(Home) Page structure.

This is my setup.typoscript

page {
    typeNum = 0
    shortcutIcon = EXT:demo_site/Resources/Public/Icons/favicon.ico

    10 = FLUIDTEMPLATE
    10 {
        templateName = TEXT
        templateName.stdWrap.cObject = CASE
        templateName.stdWrap.cObject {
            key.data = pagelayout

            pagets__default = TEXT
            pagets__default.value = Default

            pagets__2column = TEXT
            pagets__2column.value = 2column

            pagets__1column = TEXT
            pagets__1column.value = 1column

            default = TEXT
            default.value = Default

            default <.pagets__2column

Resources/private/Templates/Default.html

     <f:section name="Jumbotron">
      --------
     </f:section>
    <f:section name="2column">
    --------
    </f:section>
   <f:section name="1column">
   --------
   </f:section>

Resources/private/Layouts/default.html

<f:if condition ="{templateName} == 'Jumbotron'">
     <f:render section="Jumbotron"/>
</f:if>


  <f:if condition ="{templateName} == '2column'">
    <f:render section="2column"/>
  </f:if>

  <f:if condition ="{templateName} == '1column'">
    <f:render section="1column"/>
  </f:if>

My header footer is included successfully. But I am getting problem to render different templates. So Please tell, Do I use right if condition? if not then please tell the solution What should I do to render the different templates?

Solution

Aside from some misconceptions or typos:
You have selected the different templates but you have not provided the template name as variable to your template.

You need something like this in your FLUIDTEMPLATE object after the templateName definition:

page.10 {
    templateName = ...
    templateName.stdWrap.cObject {
        :
    }

    // copy template name to a variable:
    variables.templateName < .templateName

    // define further variables:
    variables {
        :
    }
}

It looks like you do not really use different templates but that you may want to use different partials (or sections) for different layouts.
Then you do not need different template files and the definition of page.10.templateName is not necessary. Be sure to have the construct for the fluid-variable.

you have two default assignements in your CASE object. the first will be overwritten from second. (with the same values)

you use the field pagelayout with the values usually used for the fields backend_layout and backend_layout_next_level.

maybe this is a clean solution for you:

page {
    10 = FLUIDTEMPLATE
    10 {
        templateName = Default

        variables {
            templateName = CASE
            templateName {
                key.data = levelfield:-1, backend_layout_next_level, slide
                key.override.field = backend_layout

                default = TEXT
                default.value = Default 

                pagets__default = TEXT
                pagets__default.value = Default

                pagets__2column = TEXT
                pagets__2column.value = 2column

                pagets__1column = TEXT
                pagets__1column.value = 1column

                :
            }
            :
        }
    }
}

and your template file (Default.html) should hold this call:

<f:render section="{templateName}" arguments="{_all}" />

though I would prefer to use partials instead of sections, and rename the variable to something like layout as it selects no template