How much of this do we have to do for these newbies before they unlatch from mommy's nip and start trying for themesleves... Here is a start for you, as Dolphin doesn't come with page_15.html in the base install, as it's not needed unless your modifying the page. However, for what you want page_6.html has the code and then you can simply save it as page_15.html and that will give you a start:
__include _header.html__
<div class="memberMainDiv">
<div class="memberLeftDiv">
__content_column_1__
</div>
<div class="memberRightDiv">
__content_column_2__
</div>
</div>
__include _footer.html__
Take the above code and save it in a code editor as page_15.html and then upload to your server as templates/tmpl_{tmpl}/page_15.html
Notice, it has your two columns to start out, now you can remove where it says __content_column_1__ and __content_column_2__ replace those with your traditional html <div top:10px;left:150px> type coding. Have fun and please learn to use the search function, it is your friend if you just click the box for messages instead of topics and take the time to read what it brings up instead of just the titles.