Hi Kim1234,

there's not a too newbie question to be posted here! You can easily change the text size of the entry body using the DNN's built in stylesheed editor. Login as admin, navigate to Admin > Site Settings > Stylesheet Editor. Then, at the very bottom of the textbox add this:

P {
font-size: 8px;
}

now hit the Save Stylesheet link and go back to the blog page to see if it matches your requirements. You may need to refresh the page (hit F5) to see your changes in action. Let me know if you need further help.

Best regards,
Dario Rossa