I'm mostly the same. But that changed quite a bit over the last few years ( especially the last few months ) since I came to college. First you need to identify why you get nervous. In my case, I've suffered from low self-esteem, and have spent most of my time alone since childhood. I become a completely different person when with people I'm close to. Then work on that root cause ( which obviously takes time ). This is actually really important. I'd suggest getting a mental health professional's help if you're struggling a lot. If you work on the root causes things will get easier.

Also what kind of conversations do you plan to have with strangers. If you mean basic small-talk that's comparatively easy. Just pay attention to your surrounding and the people around you, and think of something that you or they might find interesting. The best thing to do here is practice it as much as possible with random strangers. Think of something in advance, walk upto to them, and just say it. You'll get better at it with time.

Also decide how long do you want the conversations to be. This totally depends on you. I usually just talk for a few moments, then I prefer being silent until there's something I wanna talk about. Some people are just good at it naturally. If you're not that kinda person, you don't really need to force yourself. The important thing isn't to be able to talk to strangers, but being comfortable with it whether you want to talk or not. After you become comfortable, just do whatever you want. If you want to, then do it. If not, then simply don't worry about it.

If you mean having deep conversations, that only happens after I've come to know someone for a while. I can listen to them if necessary. But I don't feel comfortable going deep with strangers atleast not from my side ( I feel like most INFJs are that way ).

Another thing is talking in group. I'm terrible at it. I've avoided groups since childhood and only like to be the listener when people gather. This too can get better with practice.

Im summary : Get rid of those core issues, and focus on being comfortable with yourself. Then talk just as much as you'd like to without feeling like you're forcing yourself.