Drupal 8.x

I'm having problems with the backup and migrate module. Whenever I try to go to another tab than the main backup one, such as restore, I get an error page saying:

The website encountered an unexpected error. Please try again later.

I have created a sub-theme of Zurb-Foundation and the front-end displays very well. In fact, I didn't realize I had a problem until I looked at the site reports. I originally thought the issue was a Drupal core problem because the errors point to type: php, and the messages point to core elements.
I get dozens of these errors when I refresh a browser page:

Notice: Array to string conversion in Drupal\Core\Asset\AssetResolver->getLibrariesToLoad() (line 110 of /Users/brett/vhosts/ddclab/core/lib/Drupal/Core/Asset/AssetResolver.php).

Except drupal_add_js() & themename.info file how many procedures to add js file in D7 & D8?

How many type of menus in D7 & D8? Please explain.

Hi Folks

I'm getting this on my home page immediately after installing Drupal 8:

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 72 bytes) in /home/johnmcc/public_html/podware.co.uk/vendor/doctrine/lexer/lib/Doctrine/Common/Lexer/AbstractLexer.php on line 265

There are no errors on installing - only the above when I go to my site

Any ideas what I need to do? I'm a novice on PHP but I've messed about with Drupal installation for a few years

Thanks
John

A quick Google search for ways to accomplish this will yield the same usual suspects: