Hehe. Well, just so you don't get too
lost into it.
I'll start off with a picture I did as example. It's singer Bjork. I just took a reference off of the internet. I did it by overlapping the tiniest and lightest strokes I could. It's a cellphone pic, but look closely enough and you can see this.
My favorite type of pen (as of today) is cartridge. Typically, these pens unscrew, you take a disposable/refillable cartridge, stab it into the nib, reassemble, and the ink will continuously flow out of it. That's what I used to do the light strokes on that picture. For $10 I got a set of 6 pen nibs and a little box of cartridges at my local craft store. Granted, these cheap pens aren't the most reliable things, and that's why they are so great for doing light strokes. Half of the time, they didn't flow smoothly. The other half, they barely flow at all.
Next is the inkwell/quill/dipping pen. These are the ones you dip into the inkwell like all the ones we picture people using 200+ years ago. There's a little hole in the nib that holds the ink and it flows down through a slit to the tip and onto the paper. The more pressure used, the more it flows. These pens are more reliable, but they have a tendency to drip. That's how that large spot there happened.Then I smudged the spot with a finger. A double no-no.
You can't really fix a mistake in pen, but that doesn't mean that something's ruined if you mess up. I don't reccommend white-out. It almost never matches the color of the paper. You can take a pen/small knife and GENTLY scratch off a line to remove it. This ruins the tooth and can change the way that the paper takes color, pencil, etc. This works best on thicker paper as it can tear a hole into thin paper, which I've also done. Practice it; it's a skill worth knowing if you're desperate.
I'm going to sum up the longest post ever posted to this forum by saying: even if you aren't sure, try it. It's good to be flexible. Practice with a pen you have on scratch paper. Index cards are my favorite. If you like it, then invest the $10-20 into getting a different type of pen, or maybe even ask your school's art teacher if they have anything you can borrow. Trying a new medium can go either way. No body else has to see it if it doesn't turn out as planned. If it does, then you've just expanded your talent a bit.
I'd love to see anything you may have tried if you care to share. A lot of the stuff that you've uploaded with outlines (like the anime people) would look pretty good done in ink. The stuff with shading will be harder because you can't smudge ink like you can smudge pencil (correct me if I'm wrong, but that's the technique I notice from the thumbnails of your uploads), but I'm sure with enough practice you'll get it. I can offer techniques and advice, but if you decide not to share, I respect that and wish you luck in other mediums.
Here's my scratchwork so you can see just
how much practice I did before each time I worked on her.