How to do an ollie for beginners?

I just learned how to skateboard 3 days ago, and I am pretty good. I want to start learning tricks now and I heard that the ollie was a very fundemental, beginners trick. I've tried it a couple of times but I am kind of scared of falling and getting hurt. How can I practice in a safe way and what are some tips for it? Everytime I try don't end up doing it properly