Theme development

I am about to build a site where the secondary links will be in vertical tabs on the side. (Please excuse the layout at the moment). Site will be shifting to Drupal, can not share the staging server URL right-now.

https://www.dbsit.com.au/

I want to be able to create the menus dynamically as the user adds more content.

What is the best way of doing background images?

I have added an image field to basic page. I want to have full screen-width images with text over them on my home page.

I have set up a css library for my theme but i'm a bit confused as to how I can access the images in my twig template (page--front.html.twig).

Thanks!!

We are in interesting project where the drupal full search form need to search also in an external php / my sql database for content.

We know what fields of a specific table of the my sql database have to be search in.

We have access to the database.

We don’t know how to connect the drupal search form with the external database table in order if someone looks for example for „online banking“ and in the database is a document for this - it will be shown with the full text search of the drupal platform.

Thanks for help & support,

César de la Cal

Kindly I need your support to help me solve my below problem.
Sometimes I open my website and I found this errors:

Notice: undefined index in drupal_theme_initialize()(line in include/theme.inc)

Notice: trying to get property of non-object in drupal_theme_initialize()(line in include/theme.inc)

Notice: trying to get property of non-object in _theme_load_registry()(line in include/theme.inc)

And all data in website disappear and this message appears:
"No front page content has been created yet"

I am new to Drupal (but have been a developer/designer for a long time) and trying to figure out the Block/View relationship as it applies to the Views Slideshow.

The main config I want to do is to set the slideshow for the frontpage only. But there will also be other content on the home page (normal text).

I have verified that the module itself and jquery.cycle is working fine. I can create a block or a view(page type) and set it to slideshow and it shows fine. It also will show in the preview with no problems.

Hello, i try a lot ways, spend all day in code modification and still no luck.

Maybe some pro's can help. :)

Problem

here admin code: http://pastebin.com/c4va0gps.
Updated admin code: http://pastebin.com/ZyVzr0ih (without align="left")