For MAC, open Command line and run below command
open -e Library/Preferences/PhpStorm2017.2/options/ide.general.xml
The ide.general.xml file should be fire up in TextEditor
Add the below under "showTipsOnStartup"
<option name="reopenLastProject" value="false" />
So the file should now look like the below
<application>
<component name="GeneralSettings">
<option name="showTipsOnStartup" value="false" />
<option name="reopenLastProject" value="false" />
</component>
<component name="Registry">
<entry key="dumb.aware.run.configurations" value="true" />
</component>
</application>
Then Save and Restart PHPSTORM. Yup. That's all
NOTE: Replace "PhpStorm2017.2" with your current PHPStorm name/version.
For Windows or Linux, locate the file and follow the same process.