Need to know about H4 travel from India to USA if h1b has only receipt notice

I have few queries, I appreciate if you could answer. I am on H1B and currently on 60 days grace period as I resigned from Company A (LCA filed for Location X) and recently got the receipt notice from employer B (LCA filed for location Y) which filed in regular processing (non premium). And my dependents already have H4 visa with Company A and visa valid till Oct 2021.

  1. So can H4 dependents travels from India to US?
  2. If yes then Can they travel Company A H4 visa or they need to wait till my H1B visa got approved from Company B?
  3. If yes can they travel from India to Location Y (which Company B mention in LCA) or they need to travel first to location X then from location X to Y.
  4. What are the documents H4 dependents needed while traveling from India to USA?