You are right to feel overwhelmed when looking at all the cameras, lenses and countless accessories that are on the market today. I remember how difficult it was for me to choose my first camera. Many of us are under a tight budget, yet we want to spend money wisely, without regrets. Furthermore, it´s not easy to find honest reviews about products. You have to dig deep, past the paid promotional adverts.
So, let´s assume you would like to get yourself a semi-professional camera. Here is where you will have to make your first choice - DSLR or mirror-less. DSLR or digital single-lens reflex cameras have a mirror inside and it diverts the light from lens to prism and then to viewfinder, where you can see exactly what camera sees. These cameras have been ruling the world of professional photography for the past decade. DSLRs are big and heavy, thus, ''looking'' professional. However, this is yet another example, where size actually doesn't matter.
Mirror-less cameras are basically the same DSLRs, just without a viewfinder. Lack of additional mirror makes camera much smaller and lighter. Furthermore, recent advancements in technology have put mirror-less cameras on par with DSLRs in terms of picture quality. In spite of all that, there are few things to consider. Most importantly lens availability. Here is where DSLRs outshine their counter parts. Maybe in few years there will be as many options as it is for DSLRs, but not yet. Another thing to consider - battery life. DSLRs run for longer. And for me, who loves night photography, it´s essential. Still, if you are interested in mirror-less cameras, i would recommend to check out Olympus E-PL7 or M1, Sony A500 or A7 or Fuji X-T1.
So lets say we are settled on DSLR. Next move is - Nikon or Canon? This question been out there for many years and no one has given a definite answer. At least an answer that would satisfy majority. It´s 50/50 and will probably stay like this for foreseeable future. Just one thing to remember, when you choose one, chances are good that you will stay with that brand for many years. First, you will get used to the layout of all the settings and options. And second, interchangeable lenses. Unfortunately lenses are produced for specific camera brands, so if you have a collection of lenses and you want to switch camera brands, you will have to sell your lenses.
Next question is, what´s your budget? If you have around 8000 USD, might as well go for Nikon D4s or Canon EOS 1Dx. Assuming you don't have that kind of money, things get harder. For an entry level go for Nikon D3300. It has newer generation 24 megapixel crop sensor (mind that actual megapixels are not that important unless you are printing huge prints), good picture quality and usually comes with a very reliable and flexible 18-55mm lens. For something more advanced, i´d recommend D5300, same size sensor as D3300, but this model has better focus system a flip out screen and few other additional options that will make your life easier.
I don´t think it´s worth going up a ladder any further. These entry level cameras are as good as any to get you going. It takes a while to learn the camera, to get used to it. Once you feel that you are somehow limited in what your camera can do - upgrade. However, by then, there will be new toys on the market.
Many don´t realize, that lenses can be as expensive or even more expensive than actual cameras and there is a good reason for that. That, however, I will explore in further entries.