Hi all. I just found a free forum to create and use. Is it OK that I create some of the same subjects that the other people created for their forums?

Sure, subjects aren't copyrighted.

You mean like the categories used here? Sure, there's nothing proprietary about that.

Hi all. I just found a free forum to create and use. Is it ok that I create some of the same subjects that the other people created for their forums?

Using segments of code is generally copyrighted(such as the source code from this site) however there are a number of sites that don't mind this and simply ask that you credit them in your source. As far as actual topics/site purpose there is nothing illegal/wrong about that. If you wanted to create a site called askmestuff(just tossing out a name) to do the same thing as this/other sites its not illegal in any way but I doubt they would want you posting questions here about trying to create a rival site.