/hoping this is the right place.

I have a Honda Civic EK hatch

Ive been given the following for free
> 12" kenwood sub (1200W peak)
> 2x 7" LCD sony screens.
so ive decided to put some sort of system in my car.

My car already has a dash in it, plain cd dash. I dont want to change this.
I think i need the following
> amp
> speakers (6x9 in boot 6" in doors tweeters.?)
> dvd player (to power the 2 screens I guess?)

Anyway the question is what to get, been reading about amps as im clueless, all i could find was peak power and ohms, still is a blur
I should be ok picking out the speakers and dvd player
but the amp needs to connect everything??? thats the hard part.
Anyone that can recommend a build?
or an amp that can do all this?

Was thinking price range around $400-500?
Ill be looking into this more tomorrow, just hoping to get some pointers for when i do.
Any help is appreciated.

You can't do anything for your budget. Best bet would be selling the screens, and concentrating on a decent headunit and front speakers (splits at bare minimum for decent sound quality).
Google absolutely everything you can find about car audio before you spend a cent, and even then make sure you've been around to a few stores, demo'd some products and gotten quotes on everything. Factor in about $180 for having both the head unit and speakers installed.

Start by having a good read over Here

Im gonna guess that your sub is a KFC-W3011...?

They will run off a smallish 2ch if youre on a budget, like a kenwood KAC-525 or the older KAC-5203 or 5202, which is a lil 350w amp you can get. dont pay more than $120 or so for it.

Pick up some front speakers - i wouldnt even worry about rears - on your budget they arent necessary, better to focus on one decent pair of fronts than two cheap pairs for front a rear.
Kenwood, clarion, and pioneer (amongst others) all do entry level component speakers (seperate 4 or 6 inch woofer cone, with a crossover and tweeter) from 120 to 150 a pair. Run them off your head unit, it'll be enough power seeing as they'll only need to do mid and high range sound - the sub will do all the low tones.
Your head unit will need at least one pair of RCA outputs to run the amp, more RCA's are a plus if you want to run other/more amps down the track.
Look at a pioneer DVH-3950MP. It is a cd/mp3 unit that also reads DVD's, and its a year or so old now so you can pick them up cheap. Itll run your front, your amp and sub, and a pair of screens no sweat.

HEAD UNIT - $300 ish - maybe cheaper.
SPLITS - $120
AMP - $120
Wiring Kit - $30 tops.

Then allow about $500 to fit all that and your screens and your done haha - but you'll get your gear you need for close to your budget!