What is Freyja's real name?

As far as I know Freyr's real name is Yngvi but how about Freyja?

I see Freyja more like her title since Freyja mean something like Lady similarly to how Freyr means something like Lord. This tells me that Freyja have or alteast have had another name the questian is what it is.

It doesn't help either that she is known for other names such as Gefn, Hörn, Mardöll, Sýr, Vanadis and Valfreyja which is names that i acctully haven't heard before but apparently exist.

Besides that does Freyja also have similarities to other dietes such as Frigg and Gullveig/Heiðr thats gave made schoolers belive that they could have been the same at some point in history. An example of this is that Freyja is married to Oðr who may just be an alternative name for Oðinn who is married to Frigg, however Freyja is known for using Seðr magic just like Gullveig/Heiðr and I don't recal Frigg being able to do that so... are we talking about 3 or even 4 different dieties here or are all of them the same? I mean Freyja already have many names attatched to her so it isn't totaly unrealistic