Открытку? Хмм... Что-то вроде отчета? Или как? Вот. Если не то, то пиши в лс.
I was on my favorite band`s concert last weekend. The name of this band is Fall Out Boy (возьмешь свою любимую группу). It was amazing! А lot of emotions, adrenaline! I am incredibly happy. They played my favorite song. I was there with my friend. This is his favorite band too. We had fun, danced. And then the drummer threw in the hall of his drum sticks. Two girls caught, and were overjoyed. Then we got autographs and took pictures with all group members. It was awesome!