Hello

and Welcome To BYC! You got some good advice above, like as mentioned the nice thing about getting pullets is you get eggs a lot faster, it is also easier to start with pullets since they don't need as much special care and attention as chicks do at the start, add if you get the birds old enough you don't have the chance of an accidental rooster ... but chicks are darn cute and often they wind up tamer since you raised them from the beginning.
With a pond/pool, be careful that the chickens can get out if they fall/fly in, they usually are fine with natural ponds because the banks grades are usually gradual and all around, but chickens can and do drown in stock tank or pool type things with steep sides if they can't figure out how to get back out.
Some people have their birds in the coop/run all the time, others let theirs free range all the time, it depends on your setup and especially the predator problems in your area. The more they are kept inside the more careful you do have to be they have enough space.
for local birds, try posting in your state thread ...
https://www.backyardchickens.com/t/270925/find-your-states-thread
I don't know about the spray, would depend on what it is (they should have a material safety data sheet you can check out) and how much if any contact the chickens would have with the sprayed area.
With breeds, check out the BYC Breeds section for member reviews of a lot of breeds
https://www.backyardchickens.com/products/category/chicken-breeds and the Henderson chicken breed chart compares a lot of popular breeds
http://www.sagehenfarmlodi.com/chooks/chooks.html most egg layer breed chickens can and will fly over four foot fences, especially when young, so you will have to have some sort of cover over the run to keep them in, trimming wings will help.
Orpingtons, Wyandottes, Australorps, Sussex and Plymouth Rocks are some popular nice tempered breeds, Easter Eggers for colored eggs, Red Sex Links are probably the best layers, but they can be bossy in a mixed flock if you decide to get more than one breed.
The dogs you will have to see what they do and how training goes, generally you will be best off to keep them separate and make sure the coop/run is dog proof.