Some room light is OK, just keep out of direct sunlight. I use one of my grow tents to dry in.
That is the million dollar question and hard to get right without some experience.
I just pinch test a smaller bud, if too wet to break up and smoke then give it another day and try again. Once the smaller buds are dry enough then time to place all the buds in a container with a hygrometer and let the inner moisture sweat out for 12-24 hours and see what the RH is, open container to let out some moisture daily til they get to the sweet spot of 58-62RH.
Some growers are using moisture content meters to test the buds dryness as can be seen in the grove bag thread: