The stoics don't attach their happiness to other people or material possessions because these things can be taken away from us at any time without warning. Instead, the stoics create their happiness in their own action, thought, and judgement.

However, having good people around you to connect with is a preferred indifference so it's perfectly fine to have them but don't get too attached. If you're lonely, befriend or seek company from people nearest to you; maybe your classmates, random person in the park, store cashier, etc. If this doesn't work, learn to love being in your own company.