I'm making a website with geocites, and the first page is going to be an enter sign, with requirements underneath.
where would i put the stylesheet for this?
should i make a separeate document for the style sheet, or put it with the html of the page?
im new to html and i have no idea!

you can put it in the same stylesheet.
If you want the font to be different than your font in your other pages, you can use classes or id:

.enter {font-family:arial, verdana, tahoma;
font-size:12px;
color: #hexcode;
}

and then on your enter page:

<div class="enter"> requirements: blah blah blah</div>

Same with an id:

#enter {font-family:arial, verdana, tahoma;
font-size:12px;
color: #hexcode;
}

<div id="enter"> requirements: blah blah blah</div>

Ids are meant to be used for only one thing where classes can be used for more than one.