@discotits I'm wondering whether I may have met you during your stay in Scotland!
I'm a Gardnerian Wiccan of around 20 years now, and you do have to know what you're doing and be willing to pay a price if necessary. Like Doreen Valiente, I don't believe in the Law of Threefold Return; she thought that Gerald Gardner had made it up to appear less threatening to the society of the time while I'm more of a mind that what goes around comes around, or sow the wind and reap the whirlwind.
People can do harm by dabbling, just as people can do harm by playing with ouija boards. One thing that the traditional coven structure does is a solid training, even if you then choose to be solitary. An easy way to cover your arse is to add something like "an it harm none" or "for the good of all". Personally, I wouldn't touch spells until you have a good grasp of psychic self-defence and grounding. We still don't understand all the powers of the mind and what else is out there in the universe and planes of existence.
There is an exhilaration when you feel in touch with the power of this world and feel the gods speaking through you in ritual but your first care is to yourself and to strengthen and protect yourself. I personally have a difficult time coming back from trance so I will not let myself do that alone.
Yes, you can learn yourself, but it is a long haul, and dabblers have been hurt - you wouldn't start rewiring a house if you only had instructions for rewiring a plug.