It seems to me that the internet is saturated with videos of people writing with a full spectrum of markers, pens, brushes, pencils, even crayons...and the list goes on! It's definitely not a lack of options that presents the difficulty of choosing your lettering tools, but the overwhelm of knowing which ones to choose.
When I first took up lettering, I of course had no idea where to begin. How could anyone? I knew for sure I wanted to try my hand at writing with a nib...but even still, there are about one zillion different kinds of nibs to choose from!
I did a fair bit of reading online, but ultimately what it comes down to is good old trial + error. What works for someone else may not work as well for you, so don't hesitate to try!
So, if your method so far has been to wander the aisles of Blick in a fog (been there!), what I'd say to you is this: you won't figure it out without trying, so just take a chance on a few little pens and see what works for you! Everyone's writing style is going to be a bit varied anyway, and the tools do play a role in that, but it's not a make-or-break situation. I'm sure there are pens out there I've yet to discover that one day I'll love writing with. But that's part of the fun...so instead of giving in to overwhelm on the front end, just jump in and try a few, get to know them, and remember that there are more out there that you can try later. So basically it's exactly like looking for your pen soul mate....easy.
I don't know if I've reached that level yet, but here are a few that work for me that I've made multiple purchases of.
Here are links to where you can buy all of them. Blick is my favorite for buying in-store, and online I like Paper & Ink Arts.
If you've already gotten started and are feeling discouraged (particularly with paper + ink pairings for calligraphy - too much bleeding, not enough saturation...oh, the many woes!) just remember that every time you discover an option that doesn't work, you're that much closer to finding others that will.
There are plenty out there, I promise you. I'll have to write a separate post for inks + papers. Until then...just have fun! Try some things you've seen others using, and try some things that look like fun to you. Try some dirt-cheap options, and maybe splurge on a few that seem interesting. Splurging on a pen, after all, can mean spending $5 in many cases so...if you have five dollars then you've got little inhibition.