All of the above. I honestly can't remember how long it took for me to treat gas work (welding/brazing) as anything other than worrying. I recall that I was better at it than others on my course but that was probably because I had quite extensive experience of end-feed soldering. I then bought myself a mini gas setup similar to
this one and later invested in a BOC PortaPak oxy acetylene kit for use on cars at home (rather naughtily omitted to inform my insurance company) - still got the torch and regulators but returned the cylinders when the rental became uneconomical for the amount I was using the stuff. I had around half a cylinder of oxygen at the time and as there were no refunds wasn't going to let them have that back so took the cylinder into my garden and vented it to atmosphere. If you start thinking about your own oxy acetylene gear be aware that there are regulations about transporting cylinders - if you have cylinders on a vehicle you HAVE to carry safety data sheets but you also aren't allowed to carry the data sheets if you've not got cylinders on board.
For the little bits of brazing that I do now I use the Mapp gas Rothenberger torch which I use for plumbing and lead-loading.
For anything beyond just sticking two bits of metal together with brass you need to understand preparing a joint, how to heat it (not obvious) and where/how to feed the filler rod.