You need to get books out from your local library. Try Alevel sociology course books rather than googling the essay question.
Functionalism is like a 1950's ideal of things. It believes that structure benefits society and that everything works together and is harmonious. Families are made of a working father, a SAHM and children in the functionalist ideal. The parents are married before they have the children. Religion plays a part in functionalism as it provides a moral framework by which to live which reinforces the marriage, heterosexual, tradition rhetoric. Look up Talcott Parsons.
Marxism is the opposite to functionalism. It is a conflict theory, believing that structure in society causes conflict and is in place as a way for the rich (the bourgeoise) to exploit the labour of the poor (the proletariat). This oppression keeps the rich, rich as they own the means of production (factories, farms, media) and the poor, poor. Look up Engels & Marx.
Feminism - different types of feminism all based on patriarchal oppression. 3 examples are Marxist feminism (working class women are oppressed by rich, powerful men), Liberal feminism (acknowledges that equality has come a long way, there is still work to be done, seeks m/f equality), Radical feminism (in sociological terms! doesn't acknowledge men at all really, not seeking equality between men & women but furthering women's rights, sometimes at the expense of men's).