Question

The problems of conflicting expectations.

The importance of not selling out.

Can anyone make that sentences more simple?
cuz I don't get what those means...

I don't see a verb in either. Are these sentences, or sentence fragments? If these had verbs and objects, it would be very easy to simplify them.

Either one doesn't have any verbs.
I've just got those "theme" and I have to find pictures that fit into those "theme" and I have no clue.

For conflicting expectations, I would find a picture, for example, that shows a worker whose expectations are one thing and the employer whose expectations of that worker are higher. You may find similar situations with teacher/student; yourself/your inner self; you/your borther or sister; etc.

For not selling out, look for pictures which show a person who leaks informatin for money (selling out one's honesty), any other set up which shows a willingness to "adjust" ones moral standard for some type of gain.
I hope this helps you get started. Good luck.

Thanx, DrBob222.