Well done Liz. Very nicely said. Im going to keep a copy of this for next time Im asked.
Oh dear. That's a rabbit hole you're asking about. If we show you inside, you may never find your way out. There's no map to its tunnels, you just have to sort of explore your way through...
First thing to keep in mind is that the nib, when you use no pressure, glides along the paper on a little puddle of ink. The ink is what "lubricates" the nib. Thus, the ink can have a big impact on your writing experience. (So can the paper.)
Next thing to keep in mind is that you can buy ink samples (you'll need a converter if that pen didn't come with one). This will get you 2-4 mL of ink for $1.25 - $4 - ish (depends on store, ink, volume) to try out before you commit to a whole bottle.
Beyond that, inks have different properties which will influence which ink works best for you and your pen (not all inks work well in all pens - it's an individual sort of thing).
Some inks are "wet" - they flow easily from the nib. Other inks are "dry" - they don't flow as easily. Some inks are "lubricating" - they have some additive that gives the ink a smoother feel - these are generally (always?) wetter inks. (Some nibs are wet (they let lots of ink through quickly), some nibs are dry (they only let the smallest amount necessary through), some are in between. It's common to use a wet ink with a dry nib and vice versa - see above "not all inks work well in all pens" comment.)
Some inks are saturated (they put down a solid, vibrant line of color). Other inks are less saturated and will often "shade" (something influenced by pen, paper, and ink) - where the ink color is lighter where the pen starts a stroke and darker where the pen lifts from the page. Some inks (usually heavily saturated ones) will "sheen" - they have a metallic sheen sort of like oil on water in some color other than the ink color (e.g. blues that sheen usually sheen red). If you google image search "fountain pen ink shading" or "fountain pen ink sheen", you should see some examples.
Some inks are permanent (waterproof or more), other inks are not (one drop of water and the ink runs like the feds are after it), some partially waterproof.
Some inks take a long time to dry, others dry quickly. Some inks soak into the paper, bleed through, and / or spread out or feather (create little wisps that follow the paper fibers) and some don't (this is as much to do with the paper as the ink).
See? Rabbit hole. But a fun one.
Next is paper.
As to wet and dry inks. Its not just the ink. Its the combination of ink, pen and paper. Juggling those three variables will lead you to your favorite writing experience. I might also ad that every pen has its own ink preference. Sometimes two identical pens will perform differently with the same ink.
Best way to feel your way through he ink maze is to order up a bunch of samples. They are very cheap especially with full bottles going for between $15 and $35. Some good brands in addition to waterman and Parker: Diamine, de Atramentis, Pelican, Aurora, Iroshizuku, Visconti...the list goes on. Check out Goulet pens and look for samples. Goulet also has some pretty informative videos on pens and inks.
Another place to poke around for info on inks is jetpens.com. Across the top of the site pull down the menue for Guides. Lots of info on pens and inks. Heres one on inks to start you off. https://www.jetpens....-pen-inks/ct/71
Come back and ask if you get stumped. Good luck, and happy writing.