If your goal is to just play through all of em you might as well start with 1. It's just a fighting game after all so an arcade run will take like 30-60 minutes of your time at most. Tekken 1 is a cute little game but it's certainly not one that holds a candle to Tekken 2 imo. Like many have already said, Tekken 3 is a massive step up in general and really lays the foundation for what Tekken would become.
But again, I recommend just playin all of em at least once.