Help with the roleplaying aspect of D&D?

So D&D is great, but I'm kind of terrible at on-the-fly, verbal roleplaying. I can't say things as I think of them, and the worst part? I'm playing a bard at the moment, and his play style relies heavily on charisma, so I'm supposed to be the one in the party talking us out of situations, but I can't. Anyone have any advice? Or does it all come down to practice?

I'm sort of the same way; but it's more a matter of how I'm less of a participator and more of a listener. My current character's charisma is the lowest score, so I justify myself with that, but yeah, as a bard, I think my most simplified idea of a bard is the Memer. If you're struggling to come up with something requiring persuasion or deception, try cutting a deal with them. (One time, I tried to seduce this shopkeeper so that I could get a rare item for cheaper, but I got too drunk and forgot) It might actually be a matter of practice, but I've learned that if I'm in a pretty good mood or if I'm super into the game, I participate more and do a lot of outrageous and charismatic things.

One time my DM made me roll a persuasion check with disadvantage because of something stupid I said while trying to persuade a child to come out of hiding and talk to us…… It was that bad, and my party holds it against me as a joke still…

oH THAT'S SUCH A HUGE RIP

the other day (i'm a druid) i was a horse so that we could spend less on horse rental for a lot of traveling and i'm observant so the DM texted me saying i spotted something on the horizon, but as a horse I can't talk so i had to absolutely flip the frick out to my party's attention and then my teammate was scared to get back on me because they took damage from falling off of me

BUT ALso I have definitely had a DM like that where if I tried to make a joke he'd actually implement that into the game (we once accidentally tamed a dragon that destroyed every obstacle in our way so there was one upside to it) but also!! when it comes to checks, you could say the stupidest shit ("come out kid or we'll murder you") but win the check so as a bard I'd make a ton of jokes if i can LMAO

Well, you see, that last thing you said sounds like the opposite of what I said. I believe my exact words were: "Come on, kid. We won't hurt you. In fact, we couldn't hurt you, even if we wanted to! We're in a public place!"
I still passed the check because a have double proficiency in persuasion, so a +10 currently, but still…

Also my bard isn't the "I roll to seduce" chaos engine-type bard. He's more of a warrior poet, as the bard was intended, and he has a guild artisan background, as a baker. My explanation is that his charisma comes from him being nice and amiable, so most people are inclined to listen to him. (Best part is that he's a half-orc that wears a little chef's hat)

That's beautiful i love him also aye that's very interesting, yeah I'm pretty bad at being the talkative or contributing one in D&D, as much as I want to be better.

Yeah, I've been told it just comes with practice. I've only been playing since August, and I have improved.

Hey if it's any consolation i've been playing for like five years and i still suck LMAo (although i'm good at carrying my team occasionally)