Run as Administrator and Run as different user at the same time.

Run as different user and elevate

Go to Start > Run and type secpol.msc and hit enter to launch it (if it's available). You're looking for Local Policies > Security Options > User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode > Prompt for consent for ono-Windows binaries. The default option is "Elevate without prompting". Windows Servers has a similar option that doesn't mention "Admin Approval Mode" but it does the same thing.

But if your edition of Windows doesn't include secpol.msc you will have to do some registry hack to enable it.

SP Online version

Open SharePoint Online Management Shell or Windows PowerShell ISE in Administrator mode.

Run the below command to install the module.

Install-Module SharePointPnPPowerShellOnline

After running the above command, you will get a prompt for entering your credentials.

Click "Yes to All", when you see a message as shown below.

Once installation is completed, you will see as shown in the below screen.

Run the below Commands to get the Server Version.

Connect-PnPOnline https://mytenant.sharepoint.com

Get-PnPContext

You will see the ServerVersion (as shown below). This will be the SharePoint Online Version.

SharePoint Online - New Site Collection / Sub-site / Library

To create a New (Private) Site Collection, use the below 2 options (This activity is for SharePoint Administrators only).

1. from the  classic SharePoint admin center >> site collections >> New >> Private Site Collection
2. from Microsoft 365 admin center >> Resources >> Sites >> Add a site, 

Title: "Development" Use a meaningful name as per your requirement.
Web Site address: "/sites/" is commonly selected. We used 'dev' instead of 'Development' [short URLs are recommended].
Select a language: English 
Select a template: Team site (classic experience) 

[You can change any of the above options as per your requirements.]

You will see a message "Your Site Collection is being created. It can take 15 minutes or longer to complete this task.", which will disappear in few seconds (as shown below).

From classic SharePoint admin center >> site collections or from Microsoft 365 admin center >> Sites, You can only see site collections created with Template "Team site (classic experience)".

From modern SharePoint admin center >> sites >> Active sites, You can see all site collections created with all templates .

You can use tools like Share-gate or SharePoint Online Management Shell to view all the Site Collections created with all templates.

classic SharePoint admin center >> https://tenant-admin.sharepoint.com/_layouts/15/online/SiteCollections.aspx

modern SharePoint admin center >> https://tenant-admin.sharepoint.com/_layouts/15/online/AdminHome.aspx#/home

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Create a Subsite (This activity is for SharePoint Administrators, Site Collection Administrators and users with Full Control permissions)

Go to Site contents from the Quick Launch (Left Menu) or Settings wheel icon on the top-right side.

Site contents >> New >> Subsite

Title: Any meaningful title
Description: Any meaningful description.
Web Site Address: We used 'tt' instead of 'Team Training' [short URLs are recommended].
Select a language: English
Select a template: selected Team site (classic experience)
User permissions: selected Use unique permissions

Selecting Use same permissions as parent site will provide option to select existing groups from the parent dev site (we created in the above example)

Selecting Use unique permissions will provide option to create new groups linked to this new site. (you still have option to use an existing group)

Navigation & Navigation Inheritance: These two options are  self explanatory and are based on the business requirement.

Once completed all the above fields (as per requirement), Click on Create, will create a new Subsite.
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Create a Document library (This activity is for SharePoint Administrators, Site Collection Administrators and Users with Full Control permissions)

Go to Site contents from the Quick Launch (Left menu) or Settings wheel icon on the top-right side.

Site contents >> New >> Document library

Name: whatever entered here will be part of URL [short URLs are recommended].
Description: Any meaningful description (is Optional).
Show in site navigation: Check this box to show the library in the Quick launch (Left menu).

Click Create, will create a new Document library with ttd as Name.
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Users won't prefer having short names for the libraries. We can change the Document Library Name after it is created.

Go to Wheel icon >> Library settings.

Under General Settings >> List name, description and navigation >> enter meaningful Name (here, we entered Team Training Documents).

You can also change Description and Navigation if needed.

Once completed, Click Save.

The Quick launch (Left menu) and Document library name were updated with the new name. But the URL still shows the short name (as recommended).

By default the Document library will inherit permissions from the parent site.

Click on "Stop Inheriting Permissions" to update specific permissions for this Document library.