creating user system

Hi, i don't have any experience in creating websites and i want to build an
online translation agency Website.
one of my problems is that i want to create a user system (is it right?) which
in there translators can see list of current orders with full details and
choose from them . some other stuff like accounting, ticket sending and etc is
also needed. how to create that? i mean what programming language or plugin or
framework or etc should i use for that?
other parts of websites such as Our services and About us and Contact us can
be created using WordPress Child Themes, right?
and let's take an example. well, you go to a car wash and order them to wash your car. so an washing order from you is available for workers. price (i,g 5 $), delivery date (30 m later), Requirement (be quick plz!) and etc are also available. workers can see their previous activities list and their payments (maybe you too). they can send message to each other and ...now what their manager should do if he want to make processes online?
SORRY for bad English!

If you have absolutely no web development experience, why do you actually plan to take on a project you cannot complete? Even a beginner could not handle what all you've laid out. Think about how much harder it would be for someone with no experience.

You can see what all extensions Wordpress, Joomla, and Drupal have available for you. However, they will not be 100% to your exact specifications. In this case, beggars can't be choosers. Your only other option is to learn PHP and then start this project.

i wanna be a game developer too. so can i choose c# and ASP.NET or i should choose PHP?

For future game development...you better pick C#. Remember that ASP.NET is not a language, but an implementation. It's written in VB.NET or C#. So you could eventually kill 2 birds with one stone.

However, I use the work eventually on purpose. You can't just learn a language in a matter of hours or days. And even after learning the basics, game development is way beyond that.