Adding pluggins to a WP blog on the hosting account?

Hi warriors,

I probabaly didn't even get the question right cos I am so confused

Please could someone give me some advice here...

I have added a blog to my domain using fantastico with hostgator and that's all fine. The only problem now is that I am trying to add pluggins as they only give you the basics to start with.

I tried just downloading and activating using the pluggins provided on wordpress but I am having problems as it keeps saying there is a fatal error or it says it has activated but nothing shows up?? Do you have to do something else such as manual uploading of the pluggins onto a directory or should it just be fine just to add pluggins direct from WP.

I am trying to add the wp-o-matic in particular but it says you need to have Simple Piecore or something? nothing is ever straightforward

My other question is, how does this blog connect to my actual website domain that it has been added to on fantastico. Do I just use the anchor text links on my blog or is there some other connection.

Sorry for the complete noob question and thanks in advance.