my opponent play move 1 inferna in a combat with my infferna here at starspring. They play another inferna and wont trigger star spring. If I play another inferna, can I trigger starspring even I am not the first time a player play unit

Yes — you can trigger Star Spring even though your opponent already played a unit there this turn.

Star Spring's trigger ("The first time a player plays a non-token unit here each turn...") is tracked per player, not once across all players. Your play of an Inferna is your own first non-token unit played at Star Spring this turn, so the ability triggers for you — the same way The Dreaming Tree gives each player their own first-time draw (FAQ #6567; CR 190.6.c, 383.3.e). The "they" in the ability makes the playing player the controller of the trigger and the one who decides whether to move one of their other units there to base.

So: the opponent's second Inferna not triggering doesn't block you. As long as you haven't already played a non-token unit at Star Spring this turn, your Inferna play will put Star Spring's trigger on the chain for you. (Note: a move into combat is not a "play," so moving a unit there doesn't consume your first-time trigger — only actually playing a unit does.)