Override below property in portal-ext.properties file. Place the portal-ext.properties file in ROOT/WEB-INF/classes
1default.landing.page.path=/web/guest/my-landing-page
where:
/web/guest/my-landing-page is path to your page where you want users to land after login. /web/guest is reference to default guest(liferay) community, and not url to any actual page. After the community url, you need to provide friendly-url of your landing page (my-landing-page), which is actual liferay page.
You can achieve the same by login as administrator and go to Control Panel -> Portal (tab/section) -> Settings -> Default landing page and set value "/web/guest/my-landing-page"
kind regards,
Abhed Dekavadiya