It's definitely good to have a community of friends, something for natural introverts to consider while they are still young!
At our Church the woman's group look out for each other and for the older women - helping people to get to church, shopping, and appointments. Younger generations are going to have to consider this more - with the decline in fertility and marriage rates - people are more likely to wind up alone than in past ages.
Tangentially, I briefly read a study not long ago that found volunteering was good for your health (physical and mental), so stay connected to the world around you!
That's some excellent advice all around, right there!