If you don't have a basic understanding of anatomy and it's relation to physics, it will take you a very long time to get good at this game. If you've got some rudimentary understanding of both, this game will blow your mind!
This is a sandbox/ragdoll/fighting game based around the concept of manipulating your body to complete a goal, whether it be knocking your opponent to the ground or running through an obstacle course in an attempt to knab the best time.
It has a wide variety of settings to allow you to add variety to your matches. You could change the mod and give one of the players a sword, while leaving the other barehanded. You can edit the gravity settings to match the real world which is something I would recommend doing, as it allows you to relate your actions to those of the real world.
It has a varied community, some are idiotic, but on the most part you'll come across experienced players who are willing to help people who have less experience with the game. That is something that I really love about this game, it really encourages experienced players to help out the ones with less experience. It's rewarding for both parties. The new player learns, and the experienced player sets the new player on the road to being an opponent. Very interesting.
Take a look if you're having doubts, it's free. Find a player who knows what they're doing and have them teach you.