I am Arman Malik from pakistan, I also developer, but I want to ask you, how to install Forum Script on the WordPress?

Can't answer. Here's why. Look at https://www.google.com/search?&q=Forum+script+on+WordPress which shows there are some hundred solutions so each one can vary on the "how to install."

That aside you as the developer will review a few, choose one or a few to try out and then as to the install, follow the supplier's instructions.

Wordpress is a blogging solution. To add a forum to your website, you will need to use a separate forum script. Examples are Xenforo, vBulletin, and phpBB. Each one has plugins available to create a seamless login for your users between your Wordpress blog platform and the forum platform.

Arman,
You say that you are a developer.I have a background in programming , but I am more into marketing.
I need some help with a project I took on myself.It is not big, but once I finish the project , I will be actively selling the concept/project.So it could be multiple jobs
do you think you might be able to help me?

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