There are a few sections restricted to solo only, but it’s not the default, the matchmaking is pretty quick for a random group and there’s a variety of people always looking to form groups for different tasks. One word of warning, people move fast, until you get parkour down, you might just end up running from the start to end of a level if you join groups, they’ll have completed the objectives and be waiting for you to extract.
Clans exist, and each have their own space station called a dojo that’s customized by them (cost is based on size of the clan, as a solo I was able to build up and level a clan on my own).
Voroxpete@sh.itjust.works 23 minutes ago
The core story content is single player only. The rest is multiplayer, but unlike Destiny there’s nothing that requires you to form your own group outside of the game, and all the gameplay is designed in such a way that you really don’t need to communicate. You can basically just turn on public matchmaking and get a bunch of humans who might as well be bots for all you’ll have to actually interact with them.
You can play all the content solo if you want to, but the difficulty might get a bit much, especially starting out (there are also certain game modes / mission types that really lean on having a full group).