My name is Devin, and I don't know how I would say my name properly. Would it be デビン、デビンさん、デヴィン、デヴィンさん、便乗、or something else?
Are you talking about saying your name, or writing your name?
If you're speaking it out loud, you can just pronounce it the same way you would otherwise. The pronunciation of your own name doesn't need to change just because you're speaking Japanese.
Writing it down can be trickier, and it depends a bit on how much you care whether people pronounce your name exactly right or not.
デヴィン is technically more accurate to the pronunciation, and Japanese speakers who know how to pronounce ヴィ will likely get slightly closer to the correct pronunciation of your name if it's written that way, but ヴィ is also very uncommon in Japanese (usually only used by people studying foreign languages), so many Japanese speakers might not be too used to trying to pronounce that, and may struggle a bit.
On the other hand, if you don't care about people getting it exactly perfect and want to be nicer to the Japanese speakers you might be interacting with, you can just go with デビン instead, since everyone will be pretty much guaranteed to be able to read and understand that easily.
As user3856370 mentioned, you should never use the 〜さん suffix when referring to your own name. That is only used when referring to other people's names, to show respect for other people.