People will disagree but I avoid walking street. Gawky tourists and way overpriced. I was cheated at old boxing gym but I hear that one is closed, but heads up generally that area.
I ran into this a couple of times, any shopping area will have converter plugs, whatever they are called lol. Recall 100 baht, I still have actually in front of me with round plug. GL.
If it is similar to Canada (I assume it is the same Thai rules) you can get a visa through Thai embassy for 2 months up to 6 months, although multiple entry you might need a border run after 2 months. People here are saying extend 30 days, anyway do this before you travel.