I'm really looking forward to the event at my friend's store today.
I can't wait to go to my friend's big event today.
この場合、次のような言い方ができますよ。
ーI'm really looking forward to the event at my friend's store today.
「今日、友達の店でのイベントをすごく楽しみにしているんだ」
ーI can't wait to go to my friend's big event today.
「今日、友達のビッグイベントに行くのが待ちきれない!」
ご参考まで!