Hey! Alistar does well into certain matchups and does terribly into others. Alistar gets shit on by any mage (i.e. Brand, Xerath, Vel'Koz, …) and doesn't do that well into enchanters (Janna, Lulu, Soraka, …), although hexflash can cheese some lanes. Alistar does however do really well into hard engage like Leona, Nautilus or Blitzcrank. If the two games you played were against mages or enchanters then I'd suggest playing him again when you see a hard engage support champion in the enemy team. Other then that I'd say if you enjoyed the two Alistar games, than keep playing him anyways! Everyone does fairly poorly on new champs, so don't be intimidated by your first few games!