Lessons learned...
Minimum Gear:
Reliable semi-auto pistol in a large caliber... 9mm or better. ( Mine's a .45 )
At least a dozen reliable standard capacity magazines for your pistol choice. ( I wear eight )
Reliable, high capacity pump or semi-auto shotgun in 12 gauge with at least 20" barrel...Improved Cylinder or Modified...( may be threaded for screw-in chokes ), and a tactical sling. ( my preference: Mossberg 590a1 SPX 9 shot with ghost rings )
Extended magazine tube for shotgun and appropriate shotshell carriers... ( can be on gun or body )
Smaller shot sizes in medium loadings ( 6 or 7.5 shot in 3 to 3.25 Dram loadings ) will allow you to shoot faster ( lower recoil ) and with the right choke choice they will work a lot better on steel than the expensive heavy stuff does. Smaller shot sizes also break flying and stationary clay targets more reliably than larger shot sizes do ( more shot = denser pattern = more chance of a pellet strike ).
Reliable semi-auto rifle in 5.56x45mm NATO, 7.62x51mm NATO, or 7.62x39mm M43 caliber. ( I prefer my AR )
A least a dozen or more reliable 30 round magazines for your rifle choice and a good sling. ( I like single point )
A holster and sturdy belt that securely holds firearm, mags, mag pouches and will retain it during vigorous movement. ( I use a double leg drop with mag pouches and wear tac vest with mag pouches...ya can never have enuff !! )
Cases of reliable factory or 'roll yer own' ammo that you have tested in the weapons to be used in competition. ( know it's POA/POI )
Real good tactical boots, knee & elbow pads, BDU's / tactical clothing, head cover, a MOLLE rucksack, a hydration system, foul weather gear options (GoreTex)...etc. ( Most of my gear is milspec surplus...my rucksack has a intregal hydration bladder with bite tube )
Be in good physical shape...know how to shoot from behind cover, running, kneeling, prone...study the rules of engagement...watch and go to matches, talk to people who compete ( usually very glad to be of help ) and by all means...have fun !!