Cobra sd goggles and 1s beta fpv lipos with meteor 75 pro

Whenever I use the cobra sd goggles the text seems to be blurry even though I don't need glasses and when I close one eye I can see the text perfectly well. Is it something to do with the goggles. When charging these goggles don't just plug a type c cable into it whilst the 18650 battery is plugged in and will it charge?

Last question, for the betafpv 1s lipos what is the max voltage I should be charging it at and what is the voltage that I should stop flying it at. And do you guys have a tips in general what else I should do for the best flight experience with the least errors?

Thank you