Social anxiety can make the standard advice ("just join a group!") feel more daunting than helpful — a gentler, incremental approach tends to work better.
Start smaller than feels necessary
A brief, low-stakes interaction (a regular chat with the same barista or librarian) can be a legitimate first step, building comfort before attempting a full group setting.
Consider one-on-one before group settings
A single new friend met through a smaller, structured activity may feel far more manageable than walking into a large group event.
A therapist can help build specific, gradual exposure steps if social anxiety feels like a significant barrier — this is very treatable.