As far as I know it remains untested in court, but in the UK, having a youtube channel that shows your flights is not automatically considered 'in furtherance of a business', unless it obviously is, like for example if you were doing roof surveys for people all the time, and you put up a showreel to win you more recognition / customers.
If your intention to fly is always merely recreational, and you would like a permanent cloud-based record of the flight for your own entertainment and archiving purposes I think that use of youtube is NOT in furtherance of a business, although this becomes much less defensible if that video is monetized.
And as people have said above - this makes a huge difference to the qualifications and permits you need to be flying legally. I too would recommend starting with a sub-250g, which, if you can convince yourself youtube is recreational, will only require you to get (and display on the craft) an Operator ID from the CAA which involves zero training above a basic familiarity with the rules and 11 quid a year ! This gets you the ability to fly closer than 50m to buildings and people and means you can fly in towns and parks and what the CAA describe as 'congested areas' - just not over crowds.
However, I would recommend taking the optional Flyer ID test (free) which is an easy set of 40 questions about the drone rules that show additional competence without having to go through additional training. This becomes compulsory if you want to fly anything over 250g, recreationally or otherwise. If you decide you ARE doing this commercially, then you need the full UK qualification, which involves a much greater level of training, usually costs about a grand, ends with theory and practical testing / assessment, and requires a whole new level of diligence and preparation before every flight.
As a beginner may I recommend the YT channel
Geeksvana, who have a series of videos going back years that really go into detail on the ever-changing rules and related subjects. You don't need to digest it all at once, and obviously the more recent videos are most relevant. In fact it is very easy to get bogged down / put off by the endless rules / updates and hurdles that seem to be placed in our way as we try and fly, but actually the UK is among the more sensible rule makers in the world and the CAA rules are actually the ones that will cause you the least problems !
Unfortunately, in addition to 'flying rules' we also have to pay attention to 'other' enforcement - council-imposed 'no drone' rules (some of which may be unlawful or incorrect !) / landowner privacy issues / NOTAMs and temporary flight restrictions, even SSSI's - areas of special scientific interest are sometimes off-limits to us, and it remains our responsibility to have done pre-flight checks and look-ups to make sure we are as legal as we reasonably can be in a great number of regards !
What will really end up annoying you is the vast areas of countryside and structures of historic interest that are denied to you by organisations like English Heritage and National Trust, whose paranoid, feverish, exclusionary anti-drone policies (can you sense my stance on this ?!) require constant effort to circumvent, although it is definitely possible given that they can only control where you take off and land from, NOT the airspace above their lands !
Lastly, a small caveat / warning for beginners in case it is not obvious. If you do fly sub-250 and gain access to congested areas with little or no training, these populated areas / towns you are technically allowed in are NOT ideal places to learn to fly and control your craft. I would always recommend that people who have never done this before spend at least a week of daily flights in a big empty open field, alone, or with a friend who can help 'spot' for them, while they become familiar with the craft and walk through all the functions without the stress of other people around and away from signal disturbances that we often see around towns...
