To answer the warm-up question.
I prefer warming up in the shower and then doing my excersises in front of a redlight / infrared lamp to keep constant temperature flow.
Some use electric heating pads or rice-socks that they warm up in the microwave or oven.
I’d say, start with what you’ve got, a towel that you soke with hot water also does the trick. In the course of events, you’ll try different stuff and will advance with your warm-up procedures.
The most important thing though, is to get started on PE although you might not have a perfect setting from the start. This whole thing is about trial & error and everybody constantly works to improve their exercises.
Good luck