Tryhackme is a free online platform for learning cyber security using hands-on exercises and labs.It teaches and provides you the virtual hacking environment labs, all within your browser! It is pretty much simple to get started here. Tryhackme teams have made the contents for both complete beginners and seasoned hackers.Morever they have a series of challenges just like CTF, which makes the learning process more and more interesting.It have both free and paid membership plans. And if you are just a beginner in this field then free plan will be enough for you.
I am right now personally using this and found it so exciting that I couldn't resist myself without writing an article on this topic. You can signup in it by clicking here. If you want to know more about it , then my friend Febrero has written an exceptional detailed article on it. You can reach to his article by clicking here.