Im so ashamed

So , theres a high chance Im neurodivergent (I cant get a diagnosis in the moment) and one of the symptoms that made me and my parents realize that maybe I am autistic is how I dont understand social norms sometimes . Its very selective, sometimes I act very normal , but sometimes its just embarrasing ,if it only made me look silly I wouldnt mind that much , what really sucks is when I end up being inconvenient to others . Yesterday was one of those days . So , we were just leaving college and we wait close to a cafeteria , I dont have close friends in college but I stayed close to some other girls , I standed near them said hi , and then we went to the cafeteria where the bus stops , I dont like this new point since now theres no place to sit unless we go and buy something there , and I we entered sat together and I heard them talk , we all ordered mini pizzas (who took very long to arrive) we and when we finished I was going to pay mine but then a girl said she already payed??
I think I missed something .Ugh I should have paid in the moment i ordered , I dont remember if the others paid for their own or if the same girl paid for them . In my mind we were just sitting and eating together ! I had no intention of eating for free ! I feel so ashamed , she must have felt obligated to pay for mine , imagine paying for someone you dont even know . When i found out she paid I offered my money but she refused . I had the money but I think didnt understood something and ended up being a burden . If they felt angry I didnt noticed but idk if I will be able to look at them again .