To answer your question, for USPSA and Steel Challenge, I use Midway's competition belt, AA's Alpha-X holster, and some Black Scorpion knock-offs I picked up from Amazon. For 3-gun, Uncle Mike's two-piece belt, and a Nerd Coffin holster. I don't shoot IDPA anymore.
What sport? The way I'd address IDPA is vastly different than how I'd address USPSA.
i'm not sure yet, what would you recommend i start with?
for you, NESBA B class LOL
Like others have said it depends on the game.
A good belt is a important start for either. You want something stiff and durable. For a holster kydex is probably the way to go. Depending on the game will decide if you can use a drop offset of some kind or not. For mag pouches I like multiple single pouches over any kind of double pouch. Personally I like CR-speed for USPSA and I'll use the DAA IDPA racer's for IDPA. Red hill holsters for both with different belt attachments. DAA belt in USPSA and a Shooters Connection Belt in IDPA.
I wouldn't mind finding a better IDPA belt.
I mostly shoot 3 gun, steel challenge/PSA, and a little USPSA. I use roughly the same drop/offset holsters for all, Red Hill competition and Double Alpha PDR pro2. Have an older Bladetech Black Ice for my M&P pro limited rig, and it works well enough. Use a 2 peice velcro belt, probably have 4 or 5 now, Bladetech, Double Alpha, and think an el-cheapo Scorpion. Most of my Mag holders are bladetech on tek-lok, I primarily run singles for handgun, and doubles for PCC, Taccom quad load belt caddies for shotgun shells. My gear is a little dated, and being primarily a 3 gunner, I like pouches that retain well even if they might be a little slower.
I did double alpha stuff for Mag holders because I wanted bullet out and adjustability. I also got a couple of their quad loaders for Shotgun. I have one of their holsters and a couple of holsters from Ben Stoeger which I think I like more than the one PDR ProII holster I have from Double Alpha. I am looking at an Alpha-X holster but am not sure of practicality in 3Gun as that is what I like to shoot the most. Finding good lefty gear is not easy which was why I went to the PDR pro holster first. I would probably look closely at the Ben Stoeger holsters since I found them later, and they have a great selection of Lefty stuff.