Your favorite things. You can set up a still life of mementos or other things that mean something to you.

Animals. I enjoy painting birds and squirrels, myself.

A place you've been to that was too beautiful for words.

Your dreams.

Portrait (if you are good with faces -- I used to work framing for an artist and she could paint a landscape so beautiful it would make your jaw drop. But she couldn't capture a person's essence on canvas)

Any landscape which interests you.

My House. Its clean.

try to capture the beauty of the sun in different moods: sunrise, sunset, cloudy day, dawn.....
or even clouds or perhaps rainbows.....