Do I have to Subscribe(pay money)

In order to gain access to old characters? I tried finding my old characters using the free to play version but they are not there.

No if you find the right account, all the characters will be on there.

But what about the free player 2 character slot limit? I had more than 2 characters.

Are you checking on the correct server as some where merged in the past ?
Were you on a TLP server as some of these require subscription ?

I found them... figures it would be on the last account and the last server I looked at... but thats murphy's law for you.

The free thing, on free accounts you can only make 2 characters and that is the limit. But if you already had more than that, you can still use them no problem. It just wont let you make any new ones. (unless you buy more slots or subscribe)

He is a returning account so he is Silver and will have more than 2 slots.