hi i wanna marry aela but i dunno where to get amulet of mara can anyone help?

You have to talk to a priest of Mara in Riften, he will open up a quest that allows you to purchase an Amulet of Mara and marry with certain NPCs, among who Aela. Good luck

Riften. If you donate to the priest of Mara there, he'll give you one for free.

You also sometimes find them randomly during quests.

in riften, in the bee and barb inn, also in riften in the temple of mara.

ah thanks guys big help iv bin tryin to find it all day lol