I've been studying various subjects over the past few years. Programming is one of them, I used books to learn, some have been helpful, others have made it more confusing for me.
I started with C++, moved onto DirectX and got really stuck, tried out ActionScript 3.0, went to another book on DirectX and now I'm back to C++. I wished I had done more research before I started with C++ because I did find it hard and people have mentioned it's a hard language to learn if you are new to programming and I bet I would know a lot more now if I had started off with a friendlier language.
Bear with me as I don't usually give out advice as I am still a Rookie lol, but doing this will also help me gain knowledge from other peoples posts.
1. I've never used JS, but I hear a lot of people talking about using it to begin with, but also heard others mention Python. I think JS and Python are the two that people have mentioned to most to start out with and might be considered easier languages to learn.
2. I've read that it's a good idea to learn HTML before Javascript, but I'm not 100% on this.
3. You could try searching on Google for Javascript tutorials or whatever language you plan to learn. Or you could learn from books or even from short term courses.
4. I've done a bit of searching and it should be enough to make games. I don't know how powerful it is though.
Pretty sure someone will come along and either correct me or come up with a better explanation. I'm still learning each day, but questions like these will give me the chance to do a bit of searching myself and find out something new.