If these rca connectors are confirmed to go to the speaker connector plates then you will need adapters to allow you to connect an amplifier speaker terminals to these rca plugs.
https://www.amazon.com/gp/aw/d/B01BHVTEFW/ref=mp_s_a_1_7?qid=1465690885&sr=8-7&pi=AC_SX236_SY340_FMwebp_QL65&keywords=rca+to+speaker&dpPl=1&dpID=41y3rj0IXmL&ref=plSrch
There is something you can use that allows you to connect some simple speaker wire to the rca plugs. They will accept up to around 16awg speaker wire I think. So buy some of this as well and cut short lengths to connect between the amplifier or similar unit you will need and the rca plugs. Then you just need some more of this same wire between the speaker terminals and the speakers and you should be all set.
There are many options for amplifiers to power the speakers but here are a few things to think about. First is what is your source device going to be? CD player or iPOD or bluetooth or airplay or pandora or chromecast audio. And do you want one source only going to all/some rooms or different sources to different rooms?
How many rooms do you want to activate right now and do you need to power more than one room at a time. This decides how many amp channels you will need and if you can get away with just two and a speaker selector box instead.
Do you want stereo or mono sound in each room as stereo may not work in all locations and works best with two nicely separated speakers with the right listening angle.
How will you control the sound source and power the units off and on remotely when you may not be near the amps and source devices when you want to do this. There are several solutions to this with either rf or phone based remote control and some of the solutions come with remote control optioms built in.