It's painful for me to not recommend this game because TFC is without question one of my favorite games of all time. I've played the game for thousands of hours and in hundreds of clan matches of all skill levels, but today there's virtually no servers left, and of those that are remaining, most are filled with lousy bots most the time.
If you are lucky enough to find real players, the majority of them playing today are experienced, and trust me- if you're brand new to the game, they'll absolutely crush you. I don't care how good you think you are at other FPS games, they'll run circles around you :) There's just a lot of skills to learn in TFC, and it takes most people years to become a decent player.
5-10 years ago I would recommend this game hands down. It is in my opinion one of the greatest multiplayer FPS games of all time. Sadly it's just too dead now for me to recommend.
Edit: Some people keep mentioning that it says I only have 6 hours in the game. I can assure you that I have thousands of hours, some before Steam started keeping track, and even more before Steam even existed. This was back when you connected through WON to play the game. Trust me, I know TFC. :)