FearLess Cheat Engine

I learned basics of scripting to get something like "add [eax+00000130]" for bigger amount than it gives or get the godmode by comparing or something like that. Still I find many things I can't understand how to deal with. Like "movsd xmm0, [rsi+2C]" etc.
So if someone knows any good tutorials to learn from, I would like to see them

Stephen Chapman and cheat the game on youtube are pretty good.

The official cheat engine tutorial works wonders, so I'd start there. Secondly to answer your question, that instruction essentially means move a float value to the address located at rsi+2C