Applying theme to all sites in a site collection SharePoint Foundation 2010

Question

I am working in SharePoint Foundation 2010 and want to apply a theme found in my top level site to all the remaining sites in the site collection.  I found the following bit of code on-line and put it in a script:
function Apply-SPTheme([string]$SiteUrl, [string]$webName, [string]$themeName)
 $site = new-object Microsoft.SharePoint.SPSite($SiteUrl)
 $web = $Site.OpenWeb($webName)
 $theme = [Microsoft.SharePoint.Utilities.ThmxTheme]::Open($site,"_catatlogs/theme/" + $themeName + ".thmx")
 $theme.ApplyTo($web,$false)
 $web.Update()
 $web.Dispose()
 $site.Dispose()
Apply-SPTheme "https://sitename" "" "themeName"
I call the function in the last line and the web site where I obtained the code indicated that this would put the theme in all other sites.  When I run the script I get the follwing message:
You cannot call a method on a null-valued expression. At C:\applyTheme.ps1(the script file):6 char:16
$theme.ApplyTo <<<< <$web,$false>
+CategoryInfo: InvalidOperation: (ApplyTo:String) [], RuntimeException
+FullyQualifiedErrorId:InvokeMethodOnNull
I'm a novice programmer and particularly novice on Powershell. I'm not sure I understand what the problem is or how to fix it.
I'd appreciate any help.

Answer 1

I highly recommend going back to the SharePoint 2010 site and going through all of the fundamentals.  If yo allocate an hour a day you should be caught up in two weeks.  This will save you hundreds of hours of fishing for solutions.
SharePoint is far too complex to be "guessed" at.  You will never guess at its structure. Going through the basics from the ground up will burn the structure of its design into you head.  You will then be able to find answers quickly because you
will know the documentation and how to ask the questions.
If you are only a basic Admin then your company should allow the vendor to either do the configurations or pay for you to be trained or compensate you to use your personal time for training.  It would be a win for them.
There are many very good books on SharePoint and PowerShell.  They are only good if you already have the basics of both.  One that I acquired recently is quite good at you level of involvement as it is a cookbook of solutions in PowerShell for
normal configuration and administration items that goes beyond what is available on the web site or in the basic training.
http://www.wrox.com/WileyCDA/WroxTitle/productCd-0470533331.html
I actually have the 2013 version but you should stick to the 2010 version until you are up to speed.  I bought 2013 as a catch up.  Read it over two long dinners of
Sushi and Sake.
The books run the gamut of SP from planning to admin.  They are not technical manuals and not developer books.  They are written for general administration,  You will read through quickly and then refer back to chapters as needed.  As
your SP site evolves the book will help you evolve with it.
Start by becoming extremely familiar with all of the resources on the SharePoint 2010 product site.  Post future requests that are SharePoint related to the SP forums.  They are very good with PowerShell at this time (three versions but they seem
to have caught up) - They know the product better than most here and are closer to the MS MVPs on SharePoint.  If there is a pure PowerShell issue then the people in this forum can very helpful,
Here are all of the SharePoint forums:
http://social.msdn.microsoft.com/Forums/sharepoint/en-US/home?filter=alltypes&sort=lastpostdesc&brandIgnore=true
¯\_(ツ)_/¯