Issuing three talaaqs without the knowledge of the implications and repercussions

Q: I grew up in a very harsh condition and wasn't very learned in most aspects of my Deen with Allah's grace I'm slowly getting there. Years ago in a rage of anger I issued my wife 3 talaqs without knowing the repercussions or the laws behind. I had no real Islamic knowledge of it and when my wife slapped me and told me what I did, I honestly didn't know what exactly it meant to say those words. As I was saying I grew up hearing my father telling my mother that and at that time of me saying I had no knowledge of it and we were in such a intense fight and argument. Now, after years my wife came to me and said that it stands as a divorce. Could you please guide me on this matter.

Divorcing one wife by saying her name but the another wife's name came to mind

Q: If a person has 2 wives and he, intending to divorce one says her name then explicit words of divorce like "Maryam I....(explicit words)" but at the time of sayings the words he has his other wife who he didn't want to divorce come to his mind.

Does it mean he accidentally gave divorce to the other wife (named Zainab) which he didn't intend to?

Woman going into her backyard without a scarf

Q: When I go outside to my back garden to throw something in the trashbin or do quick task, sometimes I don’t wear a headscarf or I wear it loosely. It can be inconvenient to have to put on proper hijab if I’m only going to go out for a few seconds. However, I usually peek out to see if the neighbours opposite our house have their lights on in their window and/or if they are actually looking out of the window at the time of me going to the garden. If I can see them then I will cover myself, otherwise I won’t. If a couple of strands of hair are visible then I don’t see it as an issue as they would not be able to see my hair all the way from their window. Is what I’m doing permissible?