Go to Tools > Options, and under the Appearance section select "Fonts". For starters, change the font face and size for the "Dialog" and "Menu" entries in the drop-down list. You'll need to restart SlickEdit to see those changes take effect. You may also need to update the settings for "Command Line" and "Status Line".
If the fonts are so small that you can't really see them well enough to adjust the settings, then the quickest option is to start with a clean configuration (rather than one migrated from a previous version). Just run vs -sc /path/to/my/cleanConfig. You can then move that config directory to the default location
