I used to feel like this around people.
Nowadays less, and I allow (and am happy with) myself to not having much to add to some discussions. Some people just don't have much in common with you (I've noticed this especially when working in a low-end job on holidays, where nobody apart from my bosses has higher education - and with my bosses I can go through a full workday just talking) (Education isn't everything in everything, but it's a pretty good indicator of values and interests)
I'm also relatively analytical by personality, so even with friends when they want to 'chill', I'm usually just not very active in the group. (So just chatting non-meaningful stuff is difficult, although I've improved and gotten through a few meaningless discussions with for example barbers, in the recent years, which I guess is cool.
I think the key is finding common ground - what interests you, and what interests them. So generally you have to open up your life a little bit, and also ask them about theirs. (Also don't focus only on one subject - if it's their #1 passion they live for it might be enough, but if it isn't, then you can't really delve into it that much)
Being passionate about something also gives you tools in discussions; for example I've read psychology and can recall and relate things from it, to subjects not directly about psychology, and view the topics through that lens. (But it also takes a bit of skill to use that in a way that works for the discussion - you need to evolve the discussion with what you say, so that the other person has something to latch onto and continue)
(If I were to give an example, I don't have kids nor am I very experienced with kids, but I was doing a schoolwork with a classmate and had to wait around a bit with her. She has 2 kids, and I noticed pictures drawn by them, and she mentioned having to bring them to daycare so we could work on our project. -> I can talk about my sisters child, and recall some silly stories about her, and what good and bad sides there are, and talk about similar experiences (doesn't matter if her kids do things differently - the fact that they do can push the discussion into another direction which you can continue. Usually in discussions there's also 'branches' from which you choose from as to what you want to talk about, and where to take the discussion, while doing this CONSTANTLY is ill-adviced, sometimes you can backtrack and bring up one of the points you skipped earlier, and continue on that path. Usually also you can flow towards another subject, as an example she mentioned in that discussion that she has a business based on her hobby, -> you could change subject and talk about hobbies and work)
I can't really advice as to HOW exactly practice this as I don't have experience in it - what has worked for me, is basically 'just doing it', which obviously won't work for everyone. Although I also spent(and spend..?) a lot of time analyzing others and my own behavior in social situations, and evaluate the encounters - was the other person being awkward or was it me - either way, what could I have done to make it better?
So to summarize a bit:
Accept yourself as you are - if you have nothing to say, don't feel pressured to say anything. (This doesn't mean accept things as they are and don't change yourself, but if you aren't interested in a subject, you don't necessarily have to be).
Work on your discussion skills.
Analyze your social encounters to learn from them, if you aren't happy with them.
Know yourself as a person - who you are, what are you interested in, how are you (analytical, creative, for example), how to use that as an advantage in discussion.
Get to know the other person - having a discussion with someone you don't know is quite difficult. Also getting to know them IS discussion.
This is of course just my experience and what works for me is not universal advice, so the key is finding what works for you in the end.
"If you need a safe space, see a therapist" - Jordan Peterson