Setting Up CDR File For Print

I'm trying to set up a 2" wide x  4.5" tall image for a magazine ad and could use some advice.

Can I change the dpi at this point? I ask because when I Publish to PDF the font looks sharp but the top logo isn't that sharp.

When I export a png everything looks sharp but the file size seems small, just 604 x 1354 pixels.

what should I do to get a nice sharp magazine ad??