You get only one page for posting.
The simplest way to separate posts is to assign them to categories, then use a category widget in your sidebar so readers will see a pageful of posts in a particular category. Note that Ocean MIst will display only titles of the posts.
In Ocean Mist it is possible to make a link (only a little odd looking) to a category page in your top navigation bar, so that readers will see a chronological pageful of posts on a topic of of your choice (provided those posts are assigned to that category). Note that Ocean MIst will display only titles of the posts.
Or you could set your blog to have a static front page. On that page, you could list links to category pages about "category 1," "category 2," "category 3," …
Hope this helps!