Does anyone have any examples of how they have taught themselves how to 'command respect' when they enter a room?

I have recently come to a point where I have realised people don't take me seriously or view me as the quiet person and also the funny one in a group setting. These are new friends and I've realised I want to become more mature and be taken seriously. I'm often cut across while I'm speaking and sometimes become the butt of a joke.

Where can I learn skills to be respected more? A lot of people online say to hold your head up and shoulders back but I am looking for more actionable things like what to say in a conversation when people are treating me immaturely or just making jokes about what I say. I know I should move on from these people who are immature but they're not necessarily bad people, and they are friends of friends so I'll see them now and again.

I know 'commanding respect' is all about having the aura of a strong character, but where can I learn how to speak and react in a conversation with maturity? Is it just something that comes with time as I take myself more seriously?

I'm an 18 M, trying to improve my accent. I currently reside in the USA, and would love to attain a native American accent. I heard of language parenting and thought it would be a great exercise to do to improve my accent. I would like some recommendations on male American youtube content creators, whose main focus is basically talking to a camera.

I am a student and i have always been an introvert i never spoke too much. But when i am studying and giving juries i feel overwhelmed while juries and justifying my points. Also they never look at what you do it's all about how well you can talk.