I totally understand how overwhelming getting into FPV can be when you're new to it, as you say there are a huge variety of choices in equipment and kits.
One of the first concepts you need to be clear on is the 2 different "families" (manufacturers) of equipment in the 5.8Ghz range... Boscam vs Fatshark/ImmersionRC.
Boscam compatible equipment uses frequency/channels 5705, 5685, 5665, 5645, 5885, 5905, 5925, and 5945
ImmersionRC uses frequency/channels 5740, 5760, 5780, 5800, 5820, 5840, 5860
notice the difference? Receivers tend to work better with 1 family or the other... while there are some "32 channel receivers" that list compatibility with both systems, scuttlebutt around here is they still work better with 1 set or the other, so I advise you make sure you get receiver equipment (goggles or screen) compatible with your transmitter. If you buy a kit this won't be a problem as the kit was built with compatible equipment, but if you're looking to save $ or build a system yourself you need to be aware of the above concept. btw, this difference does NOT apply to antennas... as long as you get 5.8Ghz antennas, they'll work with either set.
speaking of antennas, they are just as or more important than the core equipment you buy. A powerful transmitter with a shitty antenna attached will perform much worse than a low power transmitter with great antennas. I started off with crappy $10 antennas and a 200mW transmitter and granted I was in urban environment with high interference but I was only getting 50m max.
Now I have a Boscam TS352 500mW transmitter combined with the
FPVLR 3 antenna kit (2 spiral 1 helix) and it's rock solid out to several hundred meters, I haven't tried any super long range runs yet but it's theoretical range should easily be over 1000m with the helix antenna and diversity receiver I have.
Do you understand the concept of a "diversity receiver" ? if not I can elaborate