No, no faux pas. We were one program under the Valentina name and then the fork came and we are now Seamly2D. There was some politics at the time, but I think we’ve all grown from it and moved on. We have helped many people from the Valentina fork and with pleasure. We’re always happy to help 
If you look at the wiki page (link at the top of the page), there are some manuals that where written when Valentina and Seamly were still one program that may help you to find your way around both Valentina and Tape. Some things have changed in Valentina, but the basics are still the same.
I think I’m understanding what you’re struggling with because I have the same problem. It’s very overwhelming to be faced with tons of points that need to be measured and to figure out exactly how to use them in patterns. And my quest continues
The only advice that I can offer you is… Find a book or website, use their measurement areas that they suggest and follow their instructions to create the basic patterns on Seamly2D or Valentina. Once you have the basic pattern going, use the slash and spread methods (rotations) to move the darts around and practice converting from capped sleeves to raglan. Use the basic pattern to create the patterns you visualize and make your muslin patterns. It’s only by doing this that the measurement areas become clear. It’s only by making up an article that you will see where the instructions are actually good for a person or not and whether you actually took the measurements perfectly.
I chose Winifred Aldrich’s book to start with because she only uses 21 measurements or so and there are sites that describe in detail how to take these measurements.
While my “conscious” mind is still over-questioning everything that I’ve learnt over the past 2 years, my “automatic mind” can figure out where and how to use these measurements but my self-confidence still needs a lot of work to actually trust myself The main thing is to stop over-thinking things and to get down to doing, otherwise you get tied up in theory.
I hope this helps you a little