Hi just to point out there is
Musicians' Corner - AVForums.com which can give lots of advice.
In terms of what you are asking:
1. There are dozens of different ways to record what you are playing. Do you want to record it as audio, or midi? There are pro's and cons of both. Generally, to record either to a PC, you'll need some Digital Audio Workstation software (DAW).
2. I presume you are asking about aftertouch rather than touch sensitive? Aftertouch is desirable but not a show stopper if you are just setting out.
Also you have the option to use virtual PC based instruments now which would mean you only need a controller keyboard.
Also be careful not to buy one with small keys unless that's what you want. A full size, preferably weighted, keyboard will help you with your practice.
Be warned I started this way with a small keyboard and the corner of my study now looks like an arms race of modules, buttons and wires. It's a great hobby.