Sex help

I’m a virgin and to be honest I wanna have sex i know I’m ready I’m 18 and i know how to be safe. But the thing is I don’t wanna have a boyfriend and I’m cool with that. The thing is me and my friends we all talk about this stuff cuz we r all girl and comfortable with each other. They said that if I did that I’m a slut and I shouldn’t do it. I’ve never said anything bad about them when they tell me the thing they wanna do what should I do? And do you think it’s fine if I have sex with someone who isn’t my bf?