I'm level 16, neutral in the civil war and I only have one house, Breezehome, and I have not completed the main quest if any of these facts are needed. I just want to speak with Maramal and buy an amulet of mara so I can get a married life started. I know I have to visit the temple of Mara and that he should be there, but he isn't. Where is he?
Maramal can be found in Riften. He is either in the Temple of Mara or the Bee and Barb. Sometimes I see him roaming the market as well.
Here's a quote from the UESP wiki regarding Maramal:
Maramal is usually found either in the Temple or walking around the city. He is also found, occasionally, in The Bee and Barb.
Upon your first visit to Riften, Maramal can be located at the Bee and Barb. There is a scripted scene of him preaching that is activated upon your entrance into the inn. Until then, he will not leave and cannot be found anywhere else.
And yes, Ysolda can be married.