Do eukaryotes have membranes, do they produce their own food, and are only found in multicellular organisms?

Eukaryotes have Nucleus and Nuclear Bound organelles.

It depends whether they produce their own food or not. Some Eukaryotes does like Plants due to Chloroplasts but others can't like Fungi and animalia

Eukaryotes are only found in muticellular organisms as all unicellular organisms are prokaryotes

Hope this helps!

They do have membranes they do produce their own food and they are found in multicelled organisms

The answer is telescope.