Instead of displaying your full entry on the main journal page, you can display an entry excerpt on journal entries, with a link that users can click to view the full entry.

Step 1 - Enable Excerpt Feature

To add this, you'll need to configure the excerpt feature on your journal page.  From the Architecture tab of your Site Manager, click "configure" on your journal page, and locate the Journal Options section.  Click the box to "display excerpts in journal" and save your settings.

Step 2 - Select Excerpt Text

When creating the journal entry, highlight the text you'd like to set as your excerpt, and click the "paragraph" icon (next to the spell-check icon) in your edit window to set your entry excerpt text.

Step 4 (Optional) - Manually Set Excerpt

Alternately, you can set your excerpt text manually, by navigating to the Details & Timed Actions tab, and entering your text in the "Entry Excerpt" field there.

This will display the text of your excerpt, with the "click to read more" link.