lol rain water is fine for the plant, and reconmended (if not too acidic) if you don't have distilled or reverse osmosis water available, but it is in short supply, but use it when you can if you are only using tap water.
you didn't germinte the seed? most people reconmend if you are growing outdoors to allow it to get a few weeks old in the house before exporting it outside
yo man I was on your boat not too long ago. Just put the baby in a 1/4-1/2 gallon pot to start (I used the fabric breathable material for pots) and get yourself a little flourescant setup. Get T5 bulbs and make sure you get the right spectrum (do not get "full spectrum bulbs"). Take care of them until theyve developed a couple nodes. I put mine outside before the 4th node developed. BTW if outside in pots get yourself some hydroclay for the surface. Incredebly helpeful