If I made cash by babysitting what do I need to do to claim it

File a Self-Employed tax return - which is a regular tax return with a Schedule C attached.   You might not think of yourself as self-employed, especially if you work for an employer. However, if you got paid to do work for someone who isn't your employer, it counts as self-employment income. This could include earnings from side jobs like babysitting, driving, handyman work, web design, and so on.   Self-employment income is often reported on a 1099-MISC or 1099-K or it could be just good ole cash, but never on a W-2.

Where do I enter Schedule C?   This link has full instructions.  If you only received cash, it goes under Other Self-Employment income when you get to the income part.