Hello and Welcome to Hashnode! Good to have you here :)
imho, you should just select the nodes (communities) you are interested in and see for yourself, who is active and posts interesting stuff in these sections (take a look at discussions and stories). It is also always a good idea to follow the team and the Twitter account, because they usually push good content.
Unfortunately, everyone has different needs, so it is hard to tell you "follow X, Y and Z, because they are awesome". Find people you need :)