You did not specify what “vintage” means to you. Some folks think a 30-40 year old knife is “vintage”.

If you’re interested in knives made since early 1970s, I wouldn’t worry much about fakes. There’s not enough value (individually) in most of those knives to make it worth a counterfeiter’s time to work on them. Plus most of those are stainless steel, so therefore do not require as much care.
If your definition of “vintage” means pre-1970, identifying authentic old knives is more art than science. There is no substitute for looking at and examining the genuine article, and the only way to do that is to do it. Unfortunately there are not as many knife shows these days as there were 40-50 years ago, so find gun shows or “gun and knife” shows. Go. Find the dealers there that have old knives. Ask to see older folding knives. There may not be many amongst those selling cheap Chinese-made junk, but those selling older knives will likely help you and let you look at what they have if you don’t bother them when they’re busy with customers.
Also important is to find and buy some good reference books where you can look up pictures and descriptions of authentic knives from that period. Which books depends on what brand you’re interested in collecting. Here’s an older thread with some recommendations
viewtopic.php?t=42388. There have been few books recently published so most are now out of print. Copies are not cheap but they will save you money by avoiding wasting your money on fakes. Used book sellers like
www.abebooks.com are your best source. If you’re into old (pre-WWII) Case knives, Tom McCandless has recently published a couple of books on them. Tom is a member here (olderdogs1) and you might send him a PM about purchasing a copy. You can also probably find copies at the usual book sellers.
Storing them? Keep them in a dry, climate controlled place. Sackups brand knife rolls are great for storing knives - they’re made from silicone treated cloth, and “breathable”. I don’t recommend any other knife rolls, especially avoid anything containing leather, elastic or vinyl (Naugahyde) components. I’ve had bad experiences with both for non-stainless steel knives and nickel silver components (shields, bolsters and liners). Tips on cleaning knives can be found here
viewtopic.php?f=37&t=54157
Welcome to AAPK, and have fun with knife collecting.
Ken