Re: How to wash prefolds & how to setup overnight dipe :-)
Most people just start with a cold rinse no detergent. Then a hot wash with detergent and cold rinse. The PUL can go through the wash with them. Some people would line dry them or dry them lower temp. Some people dry on hot with no issues.
You shouldn't use regular diaper cream. Cloth friendly creams are usually oil based. I just use lanolin or olive oil, etc.
I've never used prefolds at night. I've heard you can use a newborn prefold as a doubler or 2 prefolds. Are you tri-folding or attaching it on with pin/snappi/ect?
To really achieve the feeling of dryness you might want to pick up some suede cloth or microfleece at the fabric store to make liners.
Good Luck and welcome