few questions on a new tank
 

just purchased a 65 gallon with a 40 gallon sump and my question is im going to be curing my live rock soon so should i add the live sand at the same time or can i do it after? also, for live rock and a few snails n shrimps for my clean up crew, do i need proper lighting? cause i know u can get by with curing the rock with no lights but what about the others? also, would i need a skimmer right away also? or can i wait til i actually have coral n fish to get a skimmer and proper lighting.

and what can i use to clean my salt water tank. theres some sand n salt deposit. i heard i should use vinegar?