Change the Charater size and color

[octonet]

I am new in this software no expirence in Linux etc.
I has try to edit and save the web page on the server, but is not possible
i like to change the character size to bold and the color of the different users
Can i add also the smilies and how?
Can i send exe files and how?
Or has this forum different finish set ups, like this page?

Greetings