My Plan for Starting Homebrewing

I pretty much exclusively brew 2.5 gallon batches now that I live in a smaller place. My kettle is 4 gallons, but you can always top up with cold bottled water if necessary. I have done 5 gallon and 1 gallon batches. 1's are kind of a bitch to bottle and take gravity readings. I usually only do them when testing yeast strains or when making variants.

I brewed 2, 2.5 gallon batches on Friday. I can try different recipes and usually get about 12 bombers from each batch.

 

Good thing I have multiple home brew stores in my area. However there is one shop that the owner has no clue about brewing. It's like he opened the shop just because it's a thing. Some of his ingredients are old as well.
Your kits seems good. I would upgrade to a 6 gallon bucket for the primary fermenter, a bigger brew pot, and a longer hose.
The longer hose will help when you bottle.