That's great you were put forward to be part of the befriending service! You going to do it? I don't have as much trouble talking to people if I feel like they're "worse" off in a sense than I am.
One thing I keep forgetting is that other people don't automatically make friends easily either; lots of people are shy or uncertain (if you don't know someone you don't know them, that's not easier for anyone else in that situation?) but they go ahead. I like to "practice" and get into conversations with clerks in stores sometimes, especially the grocery store; just ask how many more hours they have to work or until their break, etc. or talk about the weather. I practice looking at their nametag without them seeing me looking

so I can then say "Thank you, Name" when I'm leaving with my groceries, that sort of thing. Practicing with people who aren't as threatening and where there are "rules" of engagement and I'll be leaving soon, etc. goes well so slightly harder interactions are easier to try later.