TVHeadend is relatively easy to use once you're past the initial learning curve, but it's getting started that is difficult. It doesn't help that most of the instructional pages and videos are for either older versions, which can be quite different from the current version on some screens, or are for picking up FTA in some place in the eastern hemisphere, which is different enough from the FTA that we know and love that it can get really confusing.
The biggest part of the hurdle is getting TVHeadend to find and recognize your tuners; once you have done that you are halfway there. Then basically you need to create one network for each unique LNB output, by which I mean if you have a dual-output LNB the two outputs count as one "unique" output since they both see exactly the same channels. Then you have to assign a network to each tuner or DiSEqC switch position. And so on - it's basically trying to make all the parts fit together so that the tuner knows which dish/LNB to use for any given signal. In my experience, you have to create every mux manually if you want them to work, though maybe that's changed in the latest version. Also keep in mind that TVHeadend won't even offer some options until you have set previous options that suggest you might need them. And if you make a change and it doesn't look like it "took", either you forgot to click the Save button or link, or in a few cases you may need to refresh the page in your browser.
Try searching on something like "TVHeadend Libreelec DVB-S2 North America" without the quotes, or some similar variation, and maybe you will find something useful. The trick is to find instructions that have all those things in common - they are for TVHeadend running in Libreelec, as used to receive DVB-S2 in North America. You can try substituting Openelec for Libreelec, or DVB-S for DVB-S2, etc. but hopefully you'll find something specific to this part of the world.
