Stone advice

Good morning. I’m in northeast Ohio if that helps at all. I wanted to add a 1 foot section of stone in front of the house between future garden and home. Side of the house I wanted to convert entirely to stone. Prior homeowner did their own waterproofing proofing. So I have a couple questions

1. How far down should I dig? Couple inches, a foot, all the way down to suspected drainpipe
2. Should landscape fabric be placed as a barrier between ground dirt and stone or go all the way down to drainpipe.
3. Should I add a lipped barrier between stone and future garden.
4. Will this cause water damage? How can I ensure proper drainage?

Thanks in advance