Below is a link to a very important interview with one of the leading scholars in relation to Stoicism, Anthony Long, in which he talks (briefly) about one of the most important things to get right for anyone intested in Stoicism: a friend is not an indifferent but an external good. It is absolutely essential to get this right:
More on this topic here:
https://janniklindquist.substack.com/p/friends-family-and-community-are