For learning try out any pen/pencil/marker. If you have pens at home use these, if your not satisfied go buy a different kind. Don't spend too much money on it, you might find something that's cheap but will serve the purpose. Only con I noticed on cheap fine-liners is that they aren't suitable for water coloring.
You can use anything. My professor drew on butcher paper when he was a student, in the art of animal character design by David Colman. He did character design drawings on plain writing paper with pencil and pen.
I also suggest going for cheaper stuff. Cheap but good stuff.
I use the Pilot V7 & V5 Techpoint but replaced the ink with waterproof ink so that I can apply washes. They are technical pens which gives consistent lines. The metal tip makes it last for a long time. It's made to be disposable, I've been using mine for more than a year.
For markers, I use Copic markers but I only have grays, and warm grays. Buy the refills for them so that it's cheaper in the long run. Don't go for too many colours. If you want to have many colours, try watercolour sets.
Here's a recent marker sketch I did:
Parka Blogs <- Most dangerous blog for artists (and their wallets).