Since being a teenager I've always enjoyed photography (and collecting and using old film cameras) and that's the reason I've never wanted to turn my hobby into a business; I don't want the stress and mither of having to take a certain type of photo for a customer just because I need to pay the household bills, then there's the book-keeping, tax returns, cash-flow, marketing/advertising, professional indemnity & public liability insurance premiums, etc., No thanks, for me that would take the fun right out of a hobby I enjoy!
That said, some amateur photographers dream of turning pro, so who am I to find fault with that? If you are certain you want to take the plunge, especially in these rather uncertain financial times (if we do enter a post-Brexit recession then how likely will people be to spend money on a professional portrait photo?) then I wish you the very best of luck.
I think there's been some good advice given by some people on this thread, although it may not necessarily be what an enthusiastic and aspiring photographer wants to actually hear. However, I think quite often the best way to learn is from other people's mistakes, sorry... I mean 'life experiences'.
So, if I were starting out with your aims what camera kit would I buy? Well, I'd probably go down the full-frame route (at least with my lenses) as it's likely I'd probably end up there if my business took off. I'd weigh up my options and if budget safely allowed (without me going anywhere near debt or 'easy terms') I'd try to find a good 'low mileage', 'mint', Canon 6D and Mk1 24-105 IS L zoom from a reputable, long-established shop (that has good customer feedback and offers a good warranty) and visit the shop and try it out. I'd probably take a laptop or tablet with me, so I could view any test photos to see how they actually looked on a screen I knew. I'd see if the camera buttons and menus seemed intuitive to me and easy to operate (in comparison to any other DSLR I'd tried), and if it all checked out OK and made sense, only then would I proceed with the purchase.. after first haggling like mad for some discount and goodies like a top-quality protective lens filter and memory card thrown in free to clinch the deal!
Why a 6D with 24-105 IS L? It's a fairly small and light (for a full frame pro/enthusiast DSLR) camera that features nothing much more than is actually useful or necessary, it takes good looking photos (even on full auto - sometimes it's nice just to take a day off and just grab a snapshot or two!), it's got good low light (high-ish ISO) performance (some would say better than the 5D MkIII ) and good battery life (as long as the GPS and WiFi options are turned off) to keep me shooting longer. The 24-105 image stabilised zoom range should cover most eventualities most of the time (a bit like a Swiss Army knife), and at the price they currently change hands for second hand I shouldn't drop too much money should I ever want to sell it! A zoom range like that should enable me to see which focal length I tended to use most for the style of photography I actually found myself doing, then if I wanted something even sharper, or to give a shallower depth of field, I could buy a prime lens or a zoom with a shorter range and wider aperture, once I knew what I really needed. And all that for four or five hundred quid, that's got to be cheap lens research!
But that's just what
I'd do, people are different and other camera kit makes and models may suit them better and provide similar value for money and results for £. But I don't think I'd make a bad mistake if I at least considered a Canon 6D based kit as a pro-use starter? So what do the pro's think?