What kind of knowledge do I need to make this website by myself?

[Carita]

I want to create a website that caters to others that share my hobby. I want it to be a go-to place to find a directory for upcoming events related to this hobby/sport all over the country. I'm amazed that there isn't a site out there that has a comprehensive directory like this. I can see it becoming very popular for this reason alone.

I'd also like it to have interactive capabilities. For example, it would be cool for it to have a message board. I'd like people to be able to create accounts and fill out profiles to allow for easy social networking within the national community of people interested in this hobby without having to use something so personal, like facebook. Anyway, I'd really like to take the time to learn whatever I need to learn to create the website by myself. I don't really care if I have to study for a long time and work really hard to make the site. I am good with html and some CSS but that is where my knowledge hits a wall. What I want to know is which programming languages I need to study to set up a website that allows for account creation and interaction of members (via the forum, private messaging, and etc).

Thanks for any insight!