In regards to how to manage a one-to-one convo, the saying "fake it 'till you make it" might be a good headspace to have to begin with. Try to put less importance on making friends or being successful at it, and just try to have fun with it instead. Pretend you're an actor in a film and you're dangerously charming! And remember... conversation is really pretty simple. People, at the end of the day, like to talk about themselves - that's the number one rule! Ask questions about the other person and go from there. The plus side of this is that you take the emphasis off of yourself - what a pressure lifter?! What should you ask them? Anything, it doesn't matter! Just do it with a smile on your face.
"what do you do for a living?" "what do you study?" "how do you find uni?" "have you seen such and such a movie?" ...these all work fine, and provide a springboard for more spontaneous conversation. Tell them what you think and feel about these topics - don't be too guarded. And remember that flattery always works too and is a great icebreaker - "awesome shoes, man, where did you get them from?" Be yourself, trust yourself, and so will others.