On the tab “My Preferences”, accessible from “My Account”, you can specify the age range and the gender of people that you want to cross paths with.

Preferences are completely reciprocal: you will never be visible to a person that doesn’t match your criteria.

Once they are set, wait to cross paths with new profiles that match your preferences.

Changing preferences isn’t retroactive and, therefore, the profiles that you’ve previously crossed paths with will remain present on the Timeline.