https://switching.social is aimed at non-technical people, but there are other sites full of options for more advanced users:
https://degooglisons-internet.org/en/alternatives/ Degoogleify the Internet by @Framasoft
https://prism-break.org/en/ Prism Break, how to avoid mass surveillance programmes
https://f-droid.org/ F-Droid, an open source app store for Android phones, also on the Fediverse at @fdroidorg
(These and others are listed at:
https://switching.social/ethical-alternatives-for-advanced-users/)