First, with regard to panning, if you have good stereo speakers located in a good orientation (each speaker equidistant to your ears in the position you normally take while auditioning material), even a small amount of stereo separation can help individual parts jump out. That is especially true if using the same sound samples for multiple parts. It is easy to do with the Dorico mixer (or if using NP, you must use NP’s mixer.)
Compression has to do with dynamics and it a little more complicated than panning. The basic concept is to reduce volume of the loudest sounds. That lowers the overall sound energy. Generally this action is combined with a boost of the entire sound to bring it back up to the original loudness – this is usually called “make-up gain.” In applying the make-up gain, the softer sounds are amplified, making them easier to discern. Some compressors automatically apply the make-up gain and others require the user to do that manually. Even small amounts of compression can make the inner parts substantially easier to hear. If you go crazy with compression, then everything will have the same level of energy – no dynamics at all. Less is usually better.
That’s the basic principle. However, sound engineers often use compressors for a completely different objective. Most compressors include control over attack time and release time. In this case, “attack” is the opposite of what you would normally think. It is the attack time for the compressor. In other words, how quickly does the compressor decide to attenuate the loudest sounds. And the release determines how long the compressor remains clamped down after that transient has passed. By manipulating these timers, you can achieve a harder-sounding attack, or more pulsation in hard-driving music. For example if you have an attack time of 20 ms, then the first 20 ms of a loud sound king a kick drum will pass at full volume, then be clamped down to let other music be heard after that initial thump. Used in this manner, compression is usually applied to individual instruments. That is something that is more germane to the DAW mixing environment. For Dorico, I would add a compressor to the main output bus only and give it a quick attack time.
For a visual model, you can think of a compressor like somebody manually moving the mixer’s fader up and down to try to soften the loudest notes but let the rest of the material come through at full volume.
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On edit, I would also add that if one has been using bargain basement $24 computer speakers, one will be surprised at how much much more clarity the Dorico playback has if one were to upgrade even to a $100 set of speakers targeted at the video gamer. Some of those come with a sub-woofer that is at least decent at a satisfactory sound level.
If one is using an external audio interface, one probably already has a speaker setup targeted for the home studio. There are some very nice choices that are very affordable, such as JBL 306 at about $300/pair. If one goes with a separate woofer, then one can use smaller satellite speakers such as Mackie CRS-X at $200 for the pair. A woofer for such a studio might be the JBL LSR310S at $300 (that’s 200W with internal crossover). Nearly as good would be Mackie CR8S-XBT (a new model), but curiously that one doesn’t have XLR connectors. It uses balanced TRS cables, so it would be fine, but one would need to make sure one has balanced cables. These aren’t necessarily recommendations, and a person can easily spend thousands of dollars for high end studio monitors. But a setup such as listed here will be a real awakening if one is accustomed to using really cheap PC speakers.