If you had no direct physical contact with anyone, there's no chance of you getting an STD.
To get an STD, you need to have direct, unclothed contact - mouth to genital, genital to genital, or genital to anus. There usually needs to be rubbing, grinding or penetration.
STDs and HIV can't sort of jump from one person to another through the air.
Different activities put you at risk for different infections, but all require direct contact. HIV, for example, is only transmitted via vaginal or anal sex. Syphilis can be transmitted by oral, vaginal or anal sex, or genital grinding/rubbing while unclothed. In all infections, direct contact is required.
Since you didn't have that, you're fine. :)