If the problem is emotional, it needs coping skills. People may feel uncomfortable because they are shy, have social anxiety, are trauma survivors, etc. Some of these need different solutions:
However, all of the above may want to build some stress tolerance for unavoidable conversations. Remember these are for "rock" problems you can't change, not "clay" problems you should be working to solve.
If the problem is topical, then it can be fixed with knowledge and practice. A basic etiquette skill is memorizing a handful of "generally considered safe" topics to ramble about and a list of risky topics better left out of polite conversations.
Some resources on smalltalk:
Introspective questions are a little riskier, but can work well with friends or like-minded strangers. Ideally, you should have enough people skills to guess which of these will be fun instead of touchy with a given audience. This may be more difficult if you cannot see facial expressions or body language and have to listen for voice tone.
Another approach is to get people talking about themselves. It won't work well with shy folks, but most people will natter endlessly once you get them going. One or two open-ended questions will usually do the trick. You can wind up most scientists with "What project are you currently working on?" and they'll run for an hour or more. Average people can usually be locked onto family, pets, work, or a hobby.
Bear in mind that some people hate smalltalk and would rather sit quietly or else discuss a safe topic of mutual interest. For the latter, hobbies and causes can offer good inspiration even if it's not something either person is brilliant as, as long as it's fun.
Some basic conversation resources:
Consider also whether the problem is something other than your skills. If the people around you are boring or obnoxious, no amount of buffing your palavery will fix that. You need to look for people actually worth talking to.