Pretty sure this is the same model serger that I have. Have not had the time to figure it out, quite complicated even to set up the thread spools. 
It is a good idea to get some spool holders, as the machine does not have them.
But it’s not a serger? It’s a coverstitch machine. There’s a serger that looks very similar. But both do have spool holders on the back of it. If yours is missing, then you need to take it back to get one that does
Tomato/tomahto: From the description: “The Brother 2340CV is a sturdy cover stitch-dedicated serger”.
Does not do EVERYTHING a conventional serger does, but it DOES finish seams and do edge trimming, which is what I would use it to do, as I already have 4 or 5 other sewing machines that do seams and embroidery.
And although the apparatus at the back/top steers the threads, there is not anything to HOLD the actual spools.
I bought these:
(EDIT: perhaps you refer to the little spools home sewers get from a fabric store? I should have clarified there is not a way to hold commercial spools.)
(Edit again: not referring to making cuts by “trimming” but rather to say finishing the edges of say, knit fabrics - like a t-shirt neck.) Who knows - maybe when I figure out how to use it there will not be a way to do knit edges?