You can still get Sonar Home Studio absolutely free as a giveaway from software magazine. It's all you need to get started.
http://forum.cakewalk.com/Sonar-Home-studio-Giveaway-m3718858.aspx copy paste this; 3327-46FD-8F9A-BBC7
Here
http://www.cakewalk.com/Redeem?kl=16&promo=CM250 All DAW's will play and record external MIDI synths. But for free you can't beat the Home Studio deal. You will need an Audio interface with a stereo pair of line level inputs as well as MIDI ports to capture the audio output of the synth. .Here's a good choice for you.
https://www.sweetwater.com/store/detail/US2X2 You record the midi performance of your keyboard via the midi inputs of the interface to a midi track in your DAW, edit your mistakes, then the midi track will play the Roland sounds via the interfaces midi output port. At this point you can even change the sounds to your taste.
Once your happy with the results then you can record those sounds via the Audio outputs of the Roland to the audio inputs of the interface to an Audio track of your DAW.
Most DAWs have drum, bass keyboard and just about every instrument on earth as a VST's instruments. Some better sounding than others. Home Studio comes with Enough good sounds to get you going.
You can record drum parts using your Roland keyboard as a midi trigger for the Drum VST kits.
You can play all the instruments from your keyboard track by track you build a song.