Welcome to the greatest hobby around.

Breathable is good but depends on where you are hunting. If hunting timber or thicker brush I'd say neoprene. If hunting coastal or out of blinds breathables are good. I will usually hunt the first split with just camo pants as it is usually warm enough.

I always prefer stocking foot waders with booties to ensure good fitting shoes. I had a cheap pair of Hodgons neoprenes to start and really enjoyed them as they were durable. My breathable Simms finally got punctured by rose hedge last year and I had some cold wet hunts.

As for decoys they are pricey to get started, maybe check craigslist. Slowly build up if no luck there.

Best of luck!

When you say Texas, where exactly do you mean?

I hunt between El Campo and Palacios and wear breathables almost exclusively. I've hunted in 95 and all the way down to 23... it's all about layers. The hunt when it was 23, we had a 20mph wind with gusts up to 35-40, and I was "comfortable". That's literally the only time I thought about neoprene waders and only for a second or two.

This pair from academy isn't great but is pretty dang good for the price:
https://www.academy.com/shop/pdp/magellan-outdoors-mens-tredlite-400-breathable-wader
They will eventually leak from the seams around the shin but are good for 2 season or so.

I have a pair of Simms from my Alaska trip that are great but not really needed for just an entry level pair, IMO.

Decoys are tough to recommend... I've been really impressed with Avian-X as of late but started with a couple dozen game winners. If you're hunting where you need a bunch of decoys, just start with buying a bunch of cheap ones and slowly start upgrading into higher quality brands. They're a lot more durable, have a better finish and seem to work better.

Check out:

https://www.rogerssportinggoods.com/

https://www.mackspw.com/

I would sign up for their daily emails, unless you don't really want to spend any money.

I'd recommend rigging your dekes Texas style. I resisted for a few years and shouldn't have.

Get a decent blind bag. But beware of going too large.

Camo bandana or paint to cover your face.

Edit: I've got one of these and it's been great for retrieving birds and dekes from deeper ponds.
https://www.midwayusa.com/product/1008192995

I've hunted ducks a little. Mostly in North Texas but some in Louisiana Oklahoma Kansas North Dakota and Canada. I've had breathable side I found out about them. Started with neoprene but they are just too hot and don't dry well when damp on the inside. So I avoid them. It's all in what you wear under the waders for breathable sometimes it's shorts and once I wore bibs and was toooooo hot.

Gear buy quality shells like Kent they are fast and round and in the game of steel speed kills. Any decoy will do really but I'd suggest a good rig i.e. Lifetime decoy rigs or similar that don't tangle and Texas rig. Also motion. A Hign pulsator is worth it's weight in 6-8 motionless floaters.

Never neoprene, even if it's cold.

I say buy cheap decoys. They're marketing to hunters. Ducks don't see them the way we see them.

Go somewhere there's real ducks, not a park. Just watch them and listen. That will really help.

I buy a lot from Wings Supply. Great deals after season.

It's for the reasons above that some of my most expensive and lifelike decoys are spoonbills. It's not that I'm targeting spoonies (though I won't turn my nose at the chance to roll one up like a lawn chair) it's just that is what is actually in the marsh and on the prairie (along with teal, pintail, gadwall, wigeon).

That being said, IMO (and there's a lot more experienced waterfowlers than me in here), you are either on the spot that morning or you aren't. If you're on the X and that's where they want to be then you can have surf scoters next to mallards next to tundra swans and ducks will come right in. I think you're spread mostly makes a difference for tough days when birds aren't quite committing to your hole and maybe some sort of realism in the spread gets them to bank one more time just in range and your setup helps you scratch our a few that a poor spread may not have.