Paragon is Epic's latest FPS/MOBA hybrid, and even though its eventually going to be free to play the currently ongoing beta requires you to purchase a founder's pack before letting you in.
Since dropping money on a brand new MOBA you know nothing about isn't the smartest idea given the genre's track record, you'll be glad to hear that Paragon's free weekend will begin in only a couple of days.
As long as you create your account on the official website before May 25 (that's tomorrow) you will be able to experience everything Paragon has to offer from Thursday May 26 to Monday May 30.
Naturally, since this is an early beta test we're talking about you can expect to see some issues, potential performance problems, and missing art assets, but the core gameplay is fully present and ready for you to enjoy.
If you're looking for some help with the overall gameplay, or just want to get a quick idea of what Paragon's all about, I've done a Beginner's Guide on just that topic, so I welcome you to give it a read.