How do I get over feeling like what I have to say is not important, and not knowing that l’ll be cut off most of the time or even ignored?

I am a very quiet guy with stunted social skills due to being socially isolated for most of my life. I’m trying to be more social now, but I’m afraid to really break out of my shell. I never feel comfortable speaking out because I know that others will think they have nester things to say, and ignore me or cut me off. I am also not an attractive guy so people don’t trust what I have to say.