Hoping to get more free time next month and was wondering if it's possible to get into 3 Gun at any time or do you have to wait for a new season? Heard some guys chatting at the range about 3 Gun season and championships the other week. I've never even watched one of the competitions, but it doesn't sound very newbie friendly lol.

Just wondering if it's a year round competition where amateurs can also give it a whirl or not. Been trying to do some research on it and there doesn't seem to be any gun rules of what's legal/illegal. From what I gather, it seems to favor semiauto high capacity shotguns, handguns, and light 5.56 AR15s.

Looking at my guns, I think I'd have to go with a Tavor (EXPS/G33), Benelli M4, and a Glock 19... should be decent, right?

You can most likely go to any local club and shoot a match at any time.  Guys who talk about seasons are probably referring to the pro circuit, like the 3 Gun Nation series.

For equipment, just run what you have for a few matches.  What you have now will be more than sufficient.  You'll need a holster and a way to carry some extra shotgun shells and pistol mags - the rifle mags can go in your back pocket for now.  No need to spend any extra money until you have some experience and know that you want to stick with it.  The equipment won't be the limiting factor at first.

Awesome! I actually have a chest rig for rifle mags and a magazine holder for my Glock. Only thing I don't have set up is shotgun... which is admittedly my worst skillset by far. Any recommendations on some sort of shotgun shell holder that can fit onto a 1.5" belt? Slings needed at all for any of the guns?

I think part of why I was so intimidated is because I bumped into Jerry Miculek that day. Got to shake his hand, but uhhh ya... I was like no flipping way I'm trying lol.

Honestly, for the first few matches you can get by with just a shotgun shell pouch meant for trap shooting, if you have one.  Tear the top off a box of shells and stick it in the pouch.  Eventually you'll want some kind of shell caddy that allows you to grab 3 or 4 at a time, but I recommend not spending any money at first, even if that means just sticking shells in your back pockets for now.  Give it a try and see what other shooters are using.  

Slings are typically not used in 3 gun for most divisions.

Cargo pocket pants it is! lol

Dumb question... what kinda shotgun ammo should I buy?

Most places I've shot require 7 1/2 or 8 shot for safety reasons - you don't want it bouncing back off the steel plates and poppers.  Regular trap loads are fine.  You may need slugs depending on the stage design.

to add to what Alemonkey commented... Federal 100 pack 1 1/8oz,  7 1/2 or 8 shot size with a 3 dram equivalent load works pretty well in most shotguns... my Benelli has ripped the aluminum base off a couple of the bulk Winchester shells....if you have not shot a practical pistol match, I would suggest a couple of them first.... set up your belt with the holster and pistol magazine pouches first... then modularize the rifle and shot shell holders

Just run what ya brung. Stuff spare ammo in your pockets. When you arrive at the match, do everyone a favor and tell the Match Director that this is your first match. If he is smart,he will ask an experienced competitor to hold you hand through the experience.

You might consider shooting a pistol-only match first (USPSA or IDPA) just to get a flavor for practical shooting with less equipment complexity.