Is there a ritual significance with entering them clockwise and leaving them anti-clockwise?
No, not unless you are trying to raise a magic circle of power, however, in a druid ritual you would enter from the west and move clockwise, just a traditional thing to do. But, most druid rituals you attend will not raise a circle of protection because the druid rituals are done for public display most of the time, and the druids don’t want the press to think the druids are up to any more than re enacting history. Further, where you are going is a magical place, and you should experience some magical experience there. Good place for scrying. I would suggest fining standing stones that you like and walking three times around the stone in a clockwise direction just to let the stone know who you are. Also, I suggest always casting a circle of protection before doing any real magic. in a magic circle you will be between worlds, this world and the Celtic Otherworld, so you will need to learn how to cast a magic circle, and I suggest taking a course in Wiccan for this. beware, in learning magic with the druids, for many druids are more into history and philosophy than magic and do not know a thing about magic, or the dangers of using magic in a foolish way. in short, modern day druidry is not the best place to learn how to do magic like Merlyn. Still, there are other wrong paths in modern druidry that you must be aware of. I suggest learning about the tuatha de danann, or at least looking up who they are, for it is my strong belief that the druids are clan members of the Tuatha de danann, and remember, a clan member does not have to be related by blood, it is more like being excepted in a group. Also, watch out for druid cults, who promise you some secret knowledge if you pay them money and really check out groups before you get involved with them. the wise druid asks lots of questions.