A few of us here have been very vocal about how much AC1 sucks. Skip it and play the others. If you need some story from it just youtube it. IMO AC1 was one of the worst games ever, took a long time for me to struggle through it. AC2 however is AMAZING.
Edit: I was also playing on the xbox, I cannot imagine the movement and fighting being fun or easy on the PC. Could be wrong though.