Cadence sensor.
Decent quality fan.
There are other variables depending on what is available to you, I have my setup in front of the tv, but wives and families can get annoyed at that, it is better than a computer screen though.
I would start off with a sufferfest subscription. Trainerroad is better, but if you want to match to sufferfest vids you have to buy them seperatly, but with TR you can run a training session with any video of your choosing. But I think starting out training sessions that match the video is better.
As you see from the zwift thread, lots of people really seem to like that, I find it rather meh.
Zwift, trainerroad and sufferfest subscriptions are all in the same ballpark price wise, if you have strava premium you can get a couple of months free on zwift.