Installing Drupal

Hello! I'm starting to freak out a little bit. I have installed, deleted, re-installed, over and over and over again the latest drupal version, some old ones with distributions, etc...

anyway, my problem is I'm trying to learn this CMS but I'm not that advanced, so I was HOPING I could install Drupal and have it installed with a demonstration website fully loaded with content, so this way I can pick at each section and learn how to do this, that, etc, etc...

I am attempting to create a multi-site implementation with a shared database using Postgres schemas to differentiate the tables between sites. I am getting the following error when running install.php:

Additional uncaught exception thrown while handling exception.

Original

I'm experiencing this problem with uploaded images (logo) only. Pages show broken link icon where logo should stand.
Because I am totally new to drupal and was trying to get the feel of it first, I didn't bother at first.
installed corporateclean theme which looked fine until I switched off the standard logo and uploaded my own. Switching the standard logo back on gives it also missing.
right click>open image in new window to the missing logo on any page resulted in the following error :

Forbidden

Hi,

Dear all,
I used quiz module and Organic groups module to create and control access quiz. I was created a quiz1 and setup for anonymous user can access to quiz. So, I can't see start quiz when I access website as anonymous user.
1. How to config access quiz and take quiz in each quiz node?
2. How to increase Allowed number of attempts for a quiz?
3. When a user is locked by exceeded number of attempts. How to unlock for that user?

Please help me.
Thank you so much,

Hello everybody,
When I install used Organic groups context module. My website display a notice as below.
Notice: Trying to get property of non-object in og_context() (line 232 of sites/all/modules/og/og_context/og_context.module).

Please help me how to fix it?

Thank you so much,
Bien Hoang