Indeed, if you are new to mixing, you have a lot to learn... A good help can be the "StudioLive AI Software Reference Manual"; chapter 4.2 deals with the compressor of the fat channel (you have fat channels on all inputs and outputs). Forget the limiter. You simply don't need it, if you have all inputs channels slightly compressed (e.g. 2:1) and the outputs as well. The point is to reduce (unneeded) energy on the way to the outputs and multiple compressors create a more balanced hearing situation than one compressor at the end of the chain, which has to do all that at once.
I recommend the manual very often, because it is well written and very helpful. Get to know your equipment, experiment with it - and then read the manual. You will see that the manual explains things very well and gives good answers. You get the manual under support on the download page.
