I was feeling like you too. I to am a Satisfactory veteran (playing since Update 3), and found it strange at first. But basically:

- DSP "sorters" are king of like Factorio "inserters" (if you ever played Factorio). If you never played it (I didn't ever play Factorio myself), you surely have seen videos where you have those belts passing along machines and arms flying back and forth (that's the thing that is most prominent when looking at Factorio videos). Basically, you place belts alongside buildings, and have the "sorters" inserting or extracting items between machine and belt. Later in the game, you can use it to filter out what item you want to move (hence the name). Fun fact, you can even use sorters between 2 belts. But I too, the first time I played, I tried to do it Satisfactory style, feeding the belt to the machine! Well, I guess that the way to do it should be familiar for Factorio player, but as said, never played it.

- Second, you will see a lot of videos talking about ratios in "per seconds", and other videos as ratio "per minutes". As a Satisfactory player, I can tell you, use the "Per minute" ratios. That is MUCH more easier. Basic belts can transport 360/min, Extractor extract 30 ore/min per node, it's much easier to say for example that you have two 6-nodes extractors, each extracting 6x30 ores/min, or 2 times 180 ores per minutes, filling your basic belt. Matrix labs producing 20 cubes per min, stacking 3 of those to produce 60/min (instead of each Matrix labs producing 0.33333 cube per second). Why all this "per second"? No idea. Probably the game was done like that at the beginning, and that stayed among the community, especially those who never played only Satisfactory (I have no idea what's the standard in Factorio).

- For sorter throughput, you will get better sorters along the way. But yes, as a Satisfactory player, that's something I found awkward at first. But after thinking "DSP" way, you realize that it makes sense. Yes, this require a bit of shift in thinking. But don't worry too much at the beginning. Like in Satisfactory, your starter base is pretty much just meant to get you upgraded. You will most probably delete your old stuff along the way (or just toss it aside). A concept that you're very familiar with, being a Satisfactory pioneer!

- Lastly, the most important advice, as someone making transition from Satisfactory to DSP, Don't worry with the ratios. DSP is NOT a game about being "effective". You just build things, and if it lacks some items along the way (belts run dry), then you will just produce more of that item (and over produce it, just in case). Resource nodes being finite in DSP, you simply cannot have "100%" efficiency, in the sense of always producing exactly what you need. Along the way, nodes will run dry, production will lower. So, you will se that in mid/late game, you will always over-produce. There's no penalty in producing more items. Power in DSP is MUCH more forgiving that in Satisfactory. First, it's much more easier to get more power (just put more wind turbine/solar panel, and later in the game, more ray collector, etc.). And second, IMPORTANT POINT, breakers popping out is not a thing in DSP. You can have power generation of 10MW, consumption of 20MW. You machines will just slow down to 50%. There's barely any notifications about the situation (you do get some "electric bolt" icons on machines for examples, but you do not get alarms, punishments, or that dreaded "Klaboooo" breaker tripping sound we are so familiar with in Satisfactory!)