If you are staying in Empoli itself then the best way to get to the ground is simply strolling through the historic town itself. Inter-town buses are rather infrequent and you will save time just by walking. If you are coming from Florence – there is a train service that leaves from Santa Maria Novella – it costs just 5 Euro and takes just over 30 minutes. If you driving to the match then there are a few places to park at the stadium, but it might be best to park in the town centre and walk to the game from there.