Tryhackme is a platform with virtual machines that need to be solved through walkthroughs, which is very good for beginners and normal CTFs where you self must hack into the machines.
Rootme is another page for online hosted virtual machines to hack.
Vulnhub has machines to download and then to hack
Hackthebox has online machines to hack, but there are very limited in the free version.
Recently the launched their academy, but it is a bit more expensive than for example tryhackme and has less.
This site seems to be a community platform
Free and smale site with videos and CTFs
This site has a lot of binarys for forensic learning.
The wargames offered by the OverTheWire community can help you to learn and practice security concepts in the form of fun-filled games. Perfect for beginners.