Lots of stats (and analysis) on population, housing, gender, disability, and more.

The Demographic Yearbook (annual series) is very helpful!

Review black tabs at top of page, especially Themes, Publications, and Data. Lots of info!
Themes: Ageing, Adolescents & Youth, Capacity Development, Family Planning, Fertility & Marriage, International Migration, Mortality, Population Policies, Population Trends, Sustainable Development Goals, Urbanization

Note: this is a series, so you can find earlier editions for older information. See the Country Profile link at the bottom of the page. Note also the links at the left-hand menu bar - be sure to click on Databases and Datasets!
SEE ALSO: the UNPD Population Policies theme, which provides more info and context.

A non-governmental organization (NGO). Mosty US, but some good international//regional/country data as well.

Check out the "Search Our Publications and Projects" link

this is an example - you can edit your search syntax -- search terms and the website/organization you are searching, of course!
I might not otherwise have found this, or known about the UN's Youth Envoy
https://www.un.org/youthenvoy/globalization-migration/

also includes info on youth employment.

"WorldPopulationReview.com is an independent for-profit organization committed to delivering up-to-date global population data and demographics."

yeah, it's an 8-minute video. This National Geographic site,is more the TL;DR version...

use this to view population pyramids and get other info

"...international demographic and other statistical data."

Incudes country statistical agencies (most not in English)