Introducing yourself to potential thesis advisor you didn't attend any class with
Go for it! This is perfectly normal, not at all weird or presumptuous!
I would put together a short, well-written email where you briefly introduce yourself, indicate your interest in his research, and propose a brief meeting to discuss whatever it is you want. Something like this would probably work:

Dear Dr. Eisenhardt,
I am Ignus Ignatius, a sophomore in the Computer Science Department here at Mutant University. I am looking forward to taking your Advanced Bioinformatics course next fall; I really enjoyed the bioinformatics module in Dr. Xavier's survey class this semester).
I am currently looking for a research internship and noticed that you have several active projects listed on your lab webpage, including the development of algorithms for processing NMR spectra.
Are you or your collaborators looking for interns? If so, I would love to talk for a few minutes if/how I might fit in your group (CV attached). I'm free Friday at 2:30 during your regular office hours and have a pretty flexible schedule on Tuesdays and Wednesdays.
Thank you,
--Ignus Ignatius

I would not ask for reference recommendations unless you actually plan to read them. Similarly, I'd try show that you did as much &quot;homework&quot; as possible by referring to specific things that this professor is doing. Some people spam out literally hundreds of generic &quot;hire me&quot; emails: this never goes well for them and you do not want yours to be mistaken for one of these.
You can rarely go wrong with a polite, personalized email. At the very worst, the prof will write back to say that they are not taking students right now, or never reply at all. Nevertheless, if this makes you very nervous, you can also ask a professor that you do know to introduce you to your &quot;target.&quot; This also isn't that weird, though you do need to be careful if they work on very similar things--you probably want to avoid suggesting that the professor you already know is somehow worse.