Kinda depends—library generally isn’t the ideal space unless your library separates quiet section from talking section, in which case sure approaching someone in the talking section is nbd Joining a club or getting involved in a project helps. Friendships are made when you see the same people again and again over extended periods
Honestly I just yap, I work at a place that requires lots of human interaction and make friends through conversation with them :) another thing too tho is if ur in school make study groups, or if u have roommates (that are willing to do this) hang out with them outside of ur house lol. I’m still good friends with mine and we catch up from time to time!