Where to begin.
YES and NO. Barrel racing can be as easy or as hard as you make it! A lot of us have worked very hard to get where we're at. Lots of blood, sweat, tears and naughty horses, maybe great ones too.
First and foremost, I'd advise you seek a trainer that specializes in barrel racing. Also, in your area if you have someone that gives barrel lessons, maybe take a few and see if it's something you'd really like to do. I know spring's up and coming in my area, lots of shows coming around. Go watch! See those great runs, the meltdowns, the falls, the wins. It's a lot of work, but SO worth it.
Barrel racing requires you to be a good rider! Some gals and guys ride "daddie's money" meaning they ride the finished horses, but can't ride themselves. In any sport you have that, and you just work harder and strive to be better! I know I always have! Money can't buy you those earned wins. You have so many elements speed, agility, the lead changes, balance, good horsemanship. It's definitley something you can get started on, but take it SLOW. It's not something to jump into overnight, a few days, or weeks, it takes months even years to get yourself and your horse polished.
Check out this thread, all the HF barrel racers have contributed a lot and it was started by Drum! Barrel Racing Exercises and Drills.