The more you do it, and force yourself out of the comfort zone. Make a plan like today my goal is to ask 3 random people how their day is? Some will ignore you, some will answer, and they are people you aren’t likely to see again, so it makes your social skills get better. Yes it is scary and anxiety racking but you’ll get random answers, or rejected. It shows you the worst and best of people, and what you might encounter when making friends.