By default Windows 10 and 11 comes with PS 5.1. You can get more modern PowerShell with winget:

winget install --id Microsoft.Powershell --source winget

that's all.

You can check which versions are available with

winget search Microsoft.PowerShell

New PowerShell will be installed additionally to existing PS. In Terminal after restart you will find new profile:

• Windows PowerShell - old profile, PS 5.1
• PowerShell - new profile, PS 7.*

You can always find which PS version you run by running

get-host

Check who uses CPU:

Get-Process | Sort-Object -Descending CPU | Select-Object -First 20

Check who uses memory:

Get-Process | Sort-Object WorkingSet64 -Descending |
Select-Object Name, @{Name='Memory (MB)';Expression={[math]::Round($_.WorkingSet64/1MB,2)}} |
Select-Object -First 15

Quick memory overview (data in kilobytes):

Get-WmiObject Win32_OperatingSystem | Select-Object TotalVisibleMemorySize, FreePhysicalMemory

Calculate free memory percentage:

$os = Get-WmiObject Win32_OperatingSystem
$pctFree = [math]::Round(($os.FreePhysicalMemory / $os.TotalVisibleMemorySize) * 100, 2)
Write-Host "Memory Utilization: $pctFree% Free"  

Get 50 last messages from system EventLog:

Get-EventLog -LogName System -EntryType Error, Warning -Newest 50

Show uptime (old Windows versions):

(New-TimeSpan -Start (Get-CimInstance Win32_OperatingSystem).LastBootUpTime -End (Get-Date))

How to work with files and folders