Supplies are something that every artist needs to create. I've been drawing for decades now and I've been drawing with ink for almost a decade. I livestream on TikTok constantly nowadays and the ink pen brand I've fallen in love with are Faber Castell Pitt Artist Pens.
Below is the exact image of the pack that I buy. I like it because it has nib tip sizes .3, .5, .7 and a brush with a thin tip. I mainly use .3,.5 and the brush. A pack like this will usually last me months. That could always change depending on the size of the drawing. I also like the fact that the ink doesn't dry out like other brands. The bristles don't break off often either.
This is not the end all be all of ink pens. You can produce great artwork with other ink products. I'm recommending these because I know they work and I always use them. I've also use other products like Micron, Artist Loft and a few others.
Here are some examples of what you can create with these pens.