I have a 1099-B form from Acorns Securities, the auto-investing app. I've made about $8.35, do I really need to fill out the 1099-B form? Seems like a lot of work..

Unfortunately, the IRS requires you to  report  all your income  on your income tax return. 

Having said that, if you don't report the 1099-B, the IRS  may  send you a notice of Proposed Increase in Taxes later this year. 

They will calculate the tax due (plus interest and penalties) and you can send them a check (no amended return necessary). On $8, that might total $1 or $2 at the most.

For Acorn Securities what section do i fill out. stocks, mutual funds etc. or undistributed Captial Gains.  Monies were taken out of the account.

If you have a Form 1099-B, you need to file in the section called Stocks, Mutual funds, Bonds, Other.

This how to report your 1099-B information:

1. Select Federal from the left side menu.
2. Select Wages and Income toward the top left.
3. Scroll down/ expand the list and look for Investment Income.
4. Find Stocks, Mutual Funds, Bonds, Other and click on Start or Update to the right. 
5. On the screen titled,  Did you get a 1099-B or brokerage statement for these sales? answer Yes.
6. At this point you can import, upload  or enter manually your 1099-B.
7. Keep going until you complete the section. 

You may also have 1099-DIV or 1099-INT information. Those are both enter in the Interest and Dividends section.