Here is my advice, wait at least 2 months to wash them and then hold out for as long as you can. If you want your jeans to last a long time wash them more frequently and if you don't want them to lose dye use woolite black or a denim washing product. There is no specific time to wash them really, just do it whenever you feel like you should/want to. The longer you wait the better your fades will be but the faster your denim will wear. Since it's your first pair just do whatever because you will learn what you want to do differently with your next pair! It's hard to wear regular denim after raw denim too, so be prepared haha.
I haven't washed my selvedge yet for the 3 months I have owned them. Why would washing them make them last longer?