Please Help

[jimme a]

more noob help please
setting up my home theater ... upgrading from listening to TV speakers my whole life hehe ... so as recommended i purchased 12gauge wire as well as banana plugs. Also purchased
6ft High-quality Coaxial Audio/Video RCA CL2 Rated Cable - RG6/U 75ohm (for S/PDIF, Digital Coax, Subwoofer & Composite Video)

Noticing the back of my sub has 2 line in inputs (red and white)
Was i supposed to buy another wire similar to that one above for sub to receiver connection? ...
and second question, doesnt get more retarded than this but here goes .. lol
on the 12 gauge wire, for installing the banana plugs onto them, i have no clue about polarity ... one wire has a clear tubing and the other has a blue strip on it.. which one attaches to which banana plus? (red/white)...
thank you for assisting a clueless soul

ps : a quick response would be helpful as i can run out to "worst buy" and pick up another cable if i am indeed missing one, and finish my setup tonight..... THANKS !!!