Are autistic people gullible?

I am male and 17 and im autistic and I was wondering are we gullible? Because I do everything someone tells me and believe everything people say. I also get taken advantage of. I am really nice to people and I don't know why they say I'm so easy to pick on. I don't know how to say no and I don't want to be rude to them. I often get told your easy to pick on. I also have poor self awareness and I would just act retarded some times. I also don't know when people are playing mind games on me like when someone pretends to b my friend only to betray me. Is there a way where I can improve my social skills?