use this to view population pyramids and get other info

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

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

Incudes country statistical agencies (most not in English)

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.

See also: The Demographic Yearbook (series)

Fertility, mortality, life expectancy, and other data including international migration.