When Tor gave them away a few years ago, it gave away the first 4 novellas. And I think that was smart. The first one is fun, but like leaving the restaurant after just appetizers. I’d say give the 1st 2 (or even 3) a go to get a solid feel for them. If you are still not into it, it’s ok to drop it. But it really pays off to see what Murderbot does with itself and its new freedom.